Our Muscles①When we think of muscles, we might often picture a bodybuilder with big arm and leg muscles. But our muscles do not have to look like that to work well.②As a matter of fact, every time we write our name, we use the 20 different muscles in our hand. Every time our heart beats, we use the our cardiac muscle(心肌). When eat our food, we use our tongue muscles. We even use muscle when we open and close our eye. In fact, every time we move, we use some of the muscles in our body.③A muscle is made of tiny fibers are packed together to make a single muscle. We all have the same number of muscles about 700 or so .Men and women with big muscles simply have thicker bundles of fibers.④There are three different types of muscles in our body. Smooth muscles are the ones that we cannot control. They work quietly to keep our body running. Also, they are the oneself that help us to absorb our food. The cardiac muscle makes the heart pump blood in and out. Skeletal muscles are the ones that we can control. These are the muscles that we use to raise our handset, or ride our bicycles.⑤Even our face often uses muscles. But if we want to save our energy, try smiling instead of frowning. Remember that it takes him 17 muscles in our face to smile, but 43 muscles to frown!前5道题选项：A. What a muscle consists ofB. When we use our musclesC. How people think of musclesD. What kind of muscles we haveE. Why we have different musclesF. Why we should smile rather than frown后5道题选项：A. frowningB. a lot of fibersC. to digest foodD. to function properlyE. whenever we are happyF. whenever we do somethingMuscles don't have to be very big ______.

Our Muscles①When we think of muscles, we might often picture a bodybuilder with big arm and leg muscles. But our muscles do not have to look like that to work well.②As a matter of fact, every time we write our name, we use the 20 different muscles in our hand. Every time our heart beats, we use the our cardiac muscle(心肌). When eat our food, we use our tongue muscles. We even use muscle when we open and close our eye. In fact, every time we move, we use some of the muscles in our body.③A muscle is made of tiny fibers are packed together to make a single muscle. We all have the same number of muscles about 700 or so. Men and women with big muscles simply have thicker bundles of fibers.④There are three different types of muscles in our body. Smooth muscles are the ones that we cannot control. They work quietly to keep our body running. Also, they are the oneself that help us to absorb our food. The cardiac muscle makes the heart pump blood in and out. Skeletal muscles are the ones that we can control. These are the muscles that we use to raise our handset, or ride our bicycles.⑤Even our face often uses muscles. But if we want to save our energy, try smiling instead of frowning. Remember that it takes him 17 muscles in our face to smile, but 43 muscles to frown!前5道题选项：A. What a muscle consists ofB. When we use our musclesC. How people think of musclesD. What kind of muscles we haveE. Why we have different musclesF. Why we should smile rather than frown后5道题选项：A. frowningB. a lot of fibersC. to digest foodD. to function properlyE. whenever we are happyF. whenever we do somethingOur muscles are working ______.

Our Muscles①When we think of muscles, we might often picture a bodybuilder with big arm and leg muscles. But our muscles do not have to look like that to work well.②As a matter of fact, every time we write our name, we use the 20 different muscles in our hand. Every time our heart beats, we use the our cardiac muscle(心肌). When eat our food, we use our tongue muscles. We even use muscle when we open and close our eye. In fact, every time we move, we use some of the muscles in our body.③A muscle is made of tiny fibers are packed together to make a single muscle. We all have the same number of muscles about 700 or so. Men and women with big muscles simply have thicker bundles of fibers.④There are three different types of muscles in our body. Smooth muscles are the ones that we cannot control. They work quietly to keep our body running. Also, they are the oneself that help us to absorb our food. The cardiac muscle makes the heart pump blood in and out. Skeletal muscles are the ones that we can control. These are the muscles that we use to raise our handset, or ride our bicycles.⑤Even our face often uses muscles. But if we want to save our energy, try smiling instead of frowning. Remember that it takes him 17 muscles in our face to smile, but 43 muscles to frown!前5道题选项：A. What a muscle consists ofB. When we use our musclesC. How people think of musclesD. What kind of muscles we haveE. Why we have different musclesF. Why we should smile rather than frown后5道题选项：A. frowningB. a lot of fibersC. to digest foodD. to function properlyE. whenever we are happyF. whenever we do somethingA single muscle contains ______.

Our Muscles①When we think of muscles, we might often picture a bodybuilder with big arm and leg muscles. But our muscles do not have to look like that to work well.②As a matter of fact, every time we write our name, we use the 20 different muscles in our hand. Every time our heart beats, we use the our cardiac muscle(心肌). When eat our food, we use our tongue muscles. We even use muscle when we open and close our eye. In fact, every time we move, we use some of the muscles in our body.③A muscle is made of tiny fibers are packed together to make a single muscle. We all have the same number of muscles about 700 or so. Men and women with big muscles simply have thicker bundles of fibers.④There are three different types of muscles in our body. Smooth muscles are the ones that we cannot control. They work quietly to keep our body running. Also, they are the oneself that help us to absorb our food. The cardiac muscle makes the heart pump blood in and out. Skeletal muscles are the ones that we can control. These are the muscles that we use to raise our handset, or ride our bicycles.⑤Even our face often uses muscles. But if we want to save our energy, try smiling instead of frowning. Remember that it takes him 17 muscles in our face to smile, but 43 muscles to frown!前5道题选项：A. What a muscle consists ofB. When we use our musclesC. How people think of musclesD. What kind of muscles we haveE. Why we have different musclesF. Why we should smile rather than frown后5道题选项：A. frowningB. a lot of fibersC. to digest foodD. to function properlyE. whenever we are happyF. whenever we do somethingSmooth muscles help us ______.

Our Muscles①When we think of muscles, we might often picture a bodybuilder with big arm and leg muscles. But our muscles do not have to look like that to work well.②As a matter of fact, every time we write our name, we use the 20 different muscles in our hand. Every time our heart beats, we use the our cardiac muscle(心肌). When eat our food, we use our tongue muscles. We even use muscle when we open and close our eye. In fact, every time we move, we use some of the muscles in our body.③A muscle is made of tiny fibers are packed together to make a single muscle. We all have the same number of muscles about 700 or so. Men and women with big muscles simply have thicker bundles of fibers.④There are three different types of muscles in our body. Smooth muscles are the ones that we cannot control. They work quietly to keep our body running. Also, they are the oneself that help us to absorb our food. The cardiac muscle makes the heart pump blood in and out. Skeletal muscles are the ones that we can control. These are the muscles that we use to raise our handset, or ride our bicycles.⑤Even our face often uses muscles. But if we want to save our energy, try smiling instead of frowning. Remember that it takes him 17 muscles in our face to smile, but 43 muscles to frown!前5道题选项：A. What a muscle consists ofB. When we use our musclesC. How people think of musclesD. What kind of muscles we haveE. Why we have different musclesF. Why we should smile rather than frown后5道题选项：A. frowningB. a lot of fibersC. to digest foodD. to function properlyE. whenever we are happyF. whenever we do somethingSmiling uses less energy than ______.

Energy recycling ( 能量再利用)① Every day, people throw away a lot of rubbish. Some of the rubbish, such as food, paper and iron, rots away over a long period of time. But plastics and rubber never rot. If they are burned, they give off poisonous gases. How to get rid of these things is a big problem.② Fortunately, people are beginning to realize just how serious the whole situation is. In many countries, laws have been passed to prevent factories form sending out poisonous gases and polluted water.③ Many natural materials are becoming scarce. Scientists have found ways to take some useful things out of the waste materials and use them again. This is called recycling. Steel, iron, glass, cloth and paper can all be recycled.④ Waste water, too, can be recycled. When the waste water from factories is made clean and reused, a lot of money is saved. Waste water from a number of cities is “cleaned” before flowing back into rivers. Today, many rivers that were polluted are getting cleaner and cleaner. Fish and birds are returning to these rivers, and the water in them is no longer poisonous or dangerous to people’s health.⑤ Man is fighting a battle against pollution. Yet, the battle will not be won until everyone knows how serious the danger is, and does something to stop it.前5道题选项：A. Water recyclingB. Rubbish problemC. Fighting pollutionD. Serious situationE. Material recyclingF. Environment protection后5道题选项：A. recyclingB. polluted waterC. poisonous gasesD. pollutionE. people’s demandsF. a lot of moneyParagraph①:____.

Energy recycling ( 能量再利用)① Every day, people throw away a lot of rubbish. Some of the rubbish, such as food, paper and iron, rots away over a long period of time. But plastics and rubber never rot. If they are burned, they give off poisonous gases. How to get rid of these things is a big problem.② Fortunately, people are beginning to realize just how serious the whole situation is. In many countries, laws have been passed to prevent factories form sending out poisonous gases and polluted water.③ Many natural materials are becoming scarce. Scientists have found ways to take some useful things out of the waste materials and use them again. This is called recycling. Steel, iron, glass, cloth and paper can all be recycled.④ Waste water, too, can be recycled. When the waste water from factories is made clean and reused, a lot of money is saved. Waste water from a number of cities is “cleaned” before flowing back into rivers. Today, many rivers that were polluted are getting cleaner and cleaner. Fish and birds are returning to these rivers, and the water in them is no longer poisonous or dangerous to people’s health.⑤ Man is fighting a battle against pollution. Yet, the battle will not be won until everyone knows how serious the danger is, and does something to stop it.前5道题选项：A. Water recyclingB. Rubbish problemC. Fighting pollutionD. Serious situationE. Material recyclingF. Environment protection后5道题选项：A. recyclingB. polluted waterC. poisonous gasesD. pollutionE. people’s demandsF. a lot of moneyParagraph②:____.

Energy recycling ( 能量再利用)① Every day, people throw away a lot of rubbish. Some of the rubbish, such as food, paper and iron, rots away over a long period of time. But plastics and rubber never rot. If they are burned, they give off poisonous gases. How to get rid of these things is a big problem.② Fortunately, people are beginning to realize just how serious the whole situation is. In many countries, laws have been passed to prevent factories form sending out poisonous gases and polluted water.③ Many natural materials are becoming scarce. Scientists have found ways to take some useful things out of the waste materials and use them again. This is called recycling. Steel, iron, glass, cloth and paper can all be recycled.④ Waste water, too, can be recycled. When the waste water from factories is made clean and reused, a lot of money is saved. Waste water from a number of cities is “cleaned” before flowing back into rivers. Today, many rivers that were polluted are getting cleaner and cleaner. Fish and birds are returning to these rivers, and the water in them is no longer poisonous or dangerous to people’s health.⑤ Man is fighting a battle against pollution. Yet, the battle will not be won until everyone knows how serious the danger is, and does something to stop it.前5道题选项：A. Water recyclingB. Rubbish problemC. Fighting pollutionD. Serious situationE. Material recyclingF. Environment protection后5道题选项：A. recyclingB. polluted waterC. poisonous gasesD. pollutionE. people’s demandsF. a lot of moneyParagraph③:____.

Energy recycling ( 能量再利用)① Every day, people throw away a lot of rubbish. Some of the rubbish, such as food, paper and iron, rots away over a long period of time. But plastics and rubber never rot. If they are burned, they give off poisonous gases. How to get rid of these things is a big problem.② Fortunately, people are beginning to realize just how serious the whole situation is. In many countries, laws have been passed to prevent factories form sending out poisonous gases and polluted water.③ Many natural materials are becoming scarce. Scientists have found ways to take some useful things out of the waste materials and use them again. This is called recycling. Steel, iron, glass, cloth and paper can all be recycled.④ Waste water, too, can be recycled. When the waste water from factories is made clean and reused, a lot of money is saved. Waste water from a number of cities is “cleaned” before flowing back into rivers. Today, many rivers that were polluted are getting cleaner and cleaner. Fish and birds are returning to these rivers, and the water in them is no longer poisonous or dangerous to people’s health.⑤ Man is fighting a battle against pollution. Yet, the battle will not be won until everyone knows how serious the danger is, and does something to stop it.前5道题选项：A. Water recyclingB. Rubbish problemC. Fighting pollutionD. Serious situationE. Material recyclingF. Environment protection后5道题选项：A. recyclingB. polluted waterC. poisonous gasesD. pollutionE. people’s demandsF. a lot of moneyParagraph④: ____.

Energy recycling ( 能量再利用)① Every day, people throw away a lot of rubbish. Some of the rubbish, such as food, paper and iron, rots away over a long period of time. But plastics and rubber never rot. If they are burned, they give off poisonous gases. How to get rid of these things is a big problem.② Fortunately, people are beginning to realize just how serious the whole situation is. In many countries, laws have been passed to prevent factories form sending out poisonous gases and polluted water.③ Many natural materials are becoming scarce. Scientists have found ways to take some useful things out of the waste materials and use them again. This is called recycling. Steel, iron, glass, cloth and paper can all be recycled.④ Waste water, too, can be recycled. When the waste water from factories is made clean and reused, a lot of money is saved. Waste water from a number of cities is “cleaned” before flowing back into rivers. Today, many rivers that were polluted are getting cleaner and cleaner. Fish and birds are returning to these rivers, and the water in them is no longer poisonous or dangerous to people’s health.⑤ Man is fighting a battle against pollution. Yet, the battle will not be won until everyone knows how serious the danger is, and does something to stop it.前5道题选项：A. Water recyclingB. Rubbish problemC. Fighting pollutionD. Serious situationE. Material recyclingF. Environment protection后5道题选项：A. recyclingB. polluted waterC. poisonous gasesD. pollutionE. people’s demandsF. a lot of moneyParagraph⑤:____.