Our Muscles1．When 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.2．As 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 our cardiac muscle（心肌）When we eat our food, we use our tongue muscles. We even use muscles when we open and close our eyes. In fact, every time we move, we use some of the muscles in our body.3．A muscle is made of tiny fibers. Fiber is a type of tissue that feels a little like a rubber band. Thousands of these 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.4．There 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 ones 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 hands, or ride our bicycles.5．Even our face often uses muscles. But if we want to save our energy, try smiling instead of frowning. Remember that it takes 17 muscles in our face to smile, but 43 muscles to frown!A single muscle contains______.

Our Muscles1．When 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.2．As 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 our cardiac muscle（心肌）When we eat our food, we use our tongue muscles. We even use muscles when we open and close our eyes. In fact, every time we move, we use some of the muscles in our body.3．A muscle is made of tiny fibers. Fiber is a type of tissue that feels a little like a rubber band. Thousands of these 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.4．There 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 ones 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 hands, or ride our bicycles.5．Even our face often uses muscles. But if we want to save our energy, try smiling instead of frowning. Remember that it takes 17 muscles in our face to smile, but 43 muscles to frown!Smooth muscles help us______.

Our Muscles1．When 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.2．As 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 our cardiac muscle（心肌）When we eat our food, we use our tongue muscles. We even use muscles when we open and close our eyes. In fact, every time we move, we use some of the muscles in our body.3．A muscle is made of tiny fibers. Fiber is a type of tissue that feels a little like a rubber band. Thousands of these 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.4．There 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 ones 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 hands, or ride our bicycles.5．Even our face often uses muscles. But if we want to save our energy, try smiling instead of frowning. Remember that it takes 17 muscles in our face to smile, but 43 muscles to frown!Smiling uses less energy than______

Biological ClockWhen the sun rises on a warm and sunny day, you can see some flowers open up. When they close late in the afternoon, other flowers open.Biological rhythms（生物节律）, like the opening and closing of flowers, happen all over nature. But not all of them are daily rhythms. Some, like the beating of our heart, happen every second.______（26）Scientists use the term biological clock to describe the timing that controls biological rhythms.______（27）In some animals it is probably controlled by the brain. In plants and other living things that have no brain, it must be something else.The migration of animals happens when a signal is sent out. For example, when days become shorter, birds leave the northern parts of the world and fly south where it is warm.______（28）Humans also have biological clocks that control their daily rhythms. When people travel by plane from one continent to another, they often cross many time zones. Their internal clocks don’t seem to work correctly. We call this jet lag（时差）.______（29）People who work night shifts also have problems with their biological clocks. They may not be as active as people who work during the daytime.Biological clocks control many rhythms of life.______（30）Doctors are looking for new ways to make travelling more comfortable and medical treatment more effective.（26）_____

Biological ClockWhen the sun rises on a warm and sunny day, you can see some flowers open up. When they close late in the afternoon, other flowers open.Biological rhythms（生物节律）, like the opening and closing of flowers, happen all over nature. But not all of them are daily rhythms. Some, like the beating of our heart, happen every second.______（26）Scientists use the term biological clock to describe the timing that controls biological rhythms.______（27）In some animals it is probably controlled by the brain. In plants and other living things that have no brain, it must be something else.The migration of animals happens when a signal is sent out. For example, when days become shorter, birds leave the northern parts of the world and fly south where it is warm.______（28）Humans also have biological clocks that control their daily rhythms. When people travel by plane from one continent to another, they often cross many time zones. Their internal clocks don’t seem to work correctly. We call this jet lag（时差）.______（29）People who work night shifts also have problems with their biological clocks. They may not be as active as people who work during the daytime.Biological clocks control many rhythms of life.______（30）Doctors are looking for new ways to make travelling more comfortable and medical treatment more effective.（27）_____

Biological ClockWhen the sun rises on a warm and sunny day, you can see some flowers open up. When they close late in the afternoon, other flowers open.Biological rhythms（生物节律）, like the opening and closing of flowers, happen all over nature. But not all of them are daily rhythms. Some, like the beating of our heart, happen every second.______（26）Scientists use the term biological clock to describe the timing that controls biological rhythms.______（27）In some animals it is probably controlled by the brain. In plants and other living things that have no brain, it must be something else.The migration of animals happens when a signal is sent out. For example, when days become shorter, birds leave the northern parts of the world and fly south where it is warm.______（28）Humans also have biological clocks that control their daily rhythms. When people travel by plane from one continent to another, they often cross many time zones. Their internal clocks don’t seem to work correctly. We call this jet lag（时差）.______（29）People who work night shifts also have problems with their biological clocks. They may not be as active as people who work during the daytime.Biological clocks control many rhythms of life.______（30）Doctors are looking for new ways to make travelling more comfortable and medical treatment more effective.（28）_____

Biological ClockWhen the sun rises on a warm and sunny day, you can see some flowers open up. When they close late in the afternoon, other flowers open.Biological rhythms（生物节律）, like the opening and closing of flowers, happen all over nature. But not all of them are daily rhythms. Some, like the beating of our heart, happen every second.______（26）Scientists use the term biological clock to describe the timing that controls biological rhythms.______（27）In some animals it is probably controlled by the brain. In plants and other living things that have no brain, it must be something else.The migration of animals happens when a signal is sent out. For example, when days become shorter, birds leave the northern parts of the world and fly south where it is warm.______（28）Humans also have biological clocks that control their daily rhythms. When people travel by plane from one continent to another, they often cross many time zones. Their internal clocks don’t seem to work correctly. We call this jet lag（时差）.______（29）People who work night shifts also have problems with their biological clocks. They may not be as active as people who work during the daytime.Biological clocks control many rhythms of life.______（30）Doctors are looking for new ways to make travelling more comfortable and medical treatment more effective.（29）_____

Biological ClockWhen the sun rises on a warm and sunny day, you can see some flowers open up. When they close late in the afternoon, other flowers open.Biological rhythms（生物节律）, like the opening and closing of flowers, happen all over nature. But not all of them are daily rhythms. Some, like the beating of our heart, happen every second.______（26）Scientists use the term biological clock to describe the timing that controls biological rhythms.______（27）In some animals it is probably controlled by the brain. In plants and other living things that have no brain, it must be something else.The migration of animals happens when a signal is sent out. For example, when days become shorter, birds leave the northern parts of the world and fly south where it is warm.______（28）Humans also have biological clocks that control their daily rhythms. When people travel by plane from one continent to another, they often cross many time zones. Their internal clocks don’t seem to work correctly. We call this jet lag（时差）.______（29）People who work night shifts also have problems with their biological clocks. They may not be as active as people who work during the daytime.Biological clocks control many rhythms of life.______（30）Doctors are looking for new ways to make travelling more comfortable and medical treatment more effective.（30）_____

Life Is DifficultWhat makes life difficult is that the process of facing and solving problems is a painful one. Problems cause______（31）, anger, fear or despair. These are______（32）feelings, often as painful as any kind of physical pain. And since life______（33）an endless series of problems, it is______（34）difficult and is full of pain as well as joy.Yet it is in this process of______（35）and solving problems that life has its meaning. Problems call forth our______（36）and our wisdom. It is only because of problems that we grow______（37）and spiritually. When we want to encourage the______（38）of the human spirit, we encourage the human capacity to solve problems, just as in school we deliberately______（39）problems for our children to solve. It is through the pain of confronting and resolving that we learn. It is for this reason that______（40）people learn not to fear but actually to welcome problems and actually to welcome the pain of problems.A.meetingB.courageC.careful D.growth E.wiseF.takes G.sadness H.set I.poses J.always K.uncomfortable L.mentally

Are There Truths in Dreams?Imagine waking up after dreaming （dream） about a terrible plane crash. The next day you will make a plane journey that you have ______（1）（plan） long before. Will you get on the plane?A survey shows that you may not cancel your trip. But your dream will probably influence your ______（2）（thought） during the journey. You may feel ______（3）（worry） and find the trip much ______（4）（long） than before. So dreams may influence what we are ______（5）（real） doing while we are awake.The explanation of dreams is still a（n）______（6）（clear） area. A team of researchers are entering a new field of studies: Do dreams actually influence our ______（7）（behave）? Over the past few years, they have ______（8）（do） studies in different cultures and found out that dreams contain some______（9）（hide） truths: dreams affect the way people live and work. But researchers also tell people not to be ______（10）（easy） influenced by their dreams.