Super Sense of Small①Dogs have a surprising sense of smell. It allows them to perform excellently at search-and-rescue operations. It also enables them to detect bombs. They can even sniff（嗅）out chemical changes resulting from certain diseases. Therefore, dogs are trained to save people's lives.②Dogs begin training when they are two months old. Their owners drop them off at training centers from 9 am to 5 p. m. every weekday. During the time, trainers play hide-and-seek with the dogs to train their sense of smell. They teach the dogs to climb ladders and run past obstacles（障碍）They also expose the dogs to loud noises.③Diseases have specific smells. Although the smells are usually too subtle for human noses to detect, dogs can tell something is wrong and warn people about the problem by barking. Many people have reported that their dogs warned them of an illness.④Scientists are training dogs to detect disease. A dog is asked to sniff a wheel. Blood samples from different people are attached to the outside of the wheel. Blood from a cancer patient has a slightly different smell than blood from a healthy person. The dog must figure out which blood sample to pick.⑤Scientists are working to design an electronic nose that can sniff out cancer. To do that, they need to figure out what molecules（分子）are sent out from the cancer. Then they can create a mixture with similar smell to that of the cancer. Once scientists know which molecules match the cancer's smell, e-nose could be designed to detect cancer.Dogs are sent to training centers_____.

Super Sense of Small①Dogs have a surprising sense of smell. It allows them to perform excellently at search-and-rescue operations. It also enables them to detect bombs. They can even sniff（嗅）out chemical changes resulting from certain diseases. Therefore, dogs are trained to save people's lives.②Dogs begin training when they are two months old. Their owners drop them off at training centers from 9 am to 5 p. m. every weekday. During the time, trainers play hide-and-seek with the dogs to train their sense of smell. They teach the dogs to climb ladders and run past obstacles（障碍）They also expose the dogs to loud noises.③Diseases have specific smells. Although the smells are usually too subtle for human noses to detect, dogs can tell something is wrong and warn people about the problem by barking. Many people have reported that their dogs warned them of an illness.④Scientists are training dogs to detect disease. A dog is asked to sniff a wheel. Blood samples from different people are attached to the outside of the wheel. Blood from a cancer patient has a slightly different smell than blood from a healthy person. The dog must figure out which blood sample to pick.⑤Scientists are working to design an electronic nose that can sniff out cancer. To do that, they need to figure out what molecules（分子）are sent out from the cancer. Then they can create a mixture with similar smell to that of the cancer. Once scientists know which molecules match the cancer's smell, e-nose could be designed to detect cancer.Dogs sometimes can warn their owners_____.

Super Sense of Small①Dogs have a surprising sense of smell. It allows them to perform excellently at search-and-rescue operations. It also enables them to detect bombs. They can even sniff（嗅）out chemical changes resulting from certain diseases. Therefore, dogs are trained to save people's lives.②Dogs begin training when they are two months old. Their owners drop them off at training centers from 9 am to 5 p. m. every weekday. During the time, trainers play hide-and-seek with the dogs to train their sense of smell. They teach the dogs to climb ladders and run past obstacles（障碍）They also expose the dogs to loud noises.③Diseases have specific smells. Although the smells are usually too subtle for human noses to detect, dogs can tell something is wrong and warn people about the problem by barking. Many people have reported that their dogs warned them of an illness.④Scientists are training dogs to detect disease. A dog is asked to sniff a wheel. Blood samples from different people are attached to the outside of the wheel. Blood from a cancer patient has a slightly different smell than blood from a healthy person. The dog must figure out which blood sample to pick.⑤Scientists are working to design an electronic nose that can sniff out cancer. To do that, they need to figure out what molecules（分子）are sent out from the cancer. Then they can create a mixture with similar smell to that of the cancer. Once scientists know which molecules match the cancer's smell, e-nose could be designed to detect cancer.Dogs are trained to detect diseases_____.

Super Sense of Small①Dogs have a surprising sense of smell. It allows them to perform excellently at search-and-rescue operations. It also enables them to detect bombs. They can even sniff（嗅）out chemical changes resulting from certain diseases. Therefore, dogs are trained to save people's lives.②Dogs begin training when they are two months old. Their owners drop them off at training centers from 9 am to 5 p. m. every weekday. During the time, trainers play hide-and-seek with the dogs to train their sense of smell. They teach the dogs to climb ladders and run past obstacles（障碍）They also expose the dogs to loud noises.③Diseases have specific smells. Although the smells are usually too subtle for human noses to detect, dogs can tell something is wrong and warn people about the problem by barking. Many people have reported that their dogs warned them of an illness.④Scientists are training dogs to detect disease. A dog is asked to sniff a wheel. Blood samples from different people are attached to the outside of the wheel. Blood from a cancer patient has a slightly different smell than blood from a healthy person. The dog must figure out which blood sample to pick.⑤Scientists are working to design an electronic nose that can sniff out cancer. To do that, they need to figure out what molecules（分子）are sent out from the cancer. Then they can create a mixture with similar smell to that of the cancer. Once scientists know which molecules match the cancer's smell, e-nose could be designed to detect cancer.To design an e-nose, scientists must find out_____.

Summer SchoolIt was the first week of June. Gabi just finished her third year of high school. However, when she received her report card in the mail, she learned that she failed a semester of algebra（代数）. _____（26）Gabi was glad she had the chance to make up for the class. She can't move on to the next level in math if she doesn't pass algebra. Summer school isn't easy though. _____（27） During the regular school year, however, she has twenty weeks to do so.Summer school meant that Gabi would be stuck in a hot classroom while most of her friends were at the beach or local amusement parks. Gabi's friends didn't fail any course. _____（28）Going to summer school also meant that Gabi's family had to change their summer vacation plans.Gabi had to be in summer school from 9 a.m. to noon. _____（29）She had to be on the bus at least an hour before class started or else she would be late. The classrooms were hot since the school building was old and did not have air conditioning. When Gabi came home from school, she couldn't do whatever she wanted. She had homework to do.This was the first time Gabi had to go to summer school. _____（30）She made a promise to herself. In the fall, when regular classes begin again, she will try her hardest to pass all the courses.26._____.

Summer SchoolIt was the first week of June. Gabi just finished her third year of high school. However, when she received her report card in the mail, she learned that she failed a semester of algebra（代数）. _____（26）Gabi was glad she had the chance to make up for the class. She can't move on to the next level in math if she doesn't pass algebra. Summer school isn't easy though. _____（27） During the regular school year, however, she has twenty weeks to do so.Summer school meant that Gabi would be stuck in a hot classroom while most of her friends were at the beach or local amusement parks. Gabi's friends didn't fail any course. _____（28）Going to summer school also meant that Gabi's family had to change their summer vacation plans.Gabi had to be in summer school from 9 a.m. to noon. _____（29）She had to be on the bus at least an hour before class started or else she would be late. The classrooms were hot since the school building was old and did not have air conditioning. When Gabi came home from school, she couldn't do whatever she wanted. She had homework to do.This was the first time Gabi had to go to summer school. _____（30）She made a promise to herself. In the fall, when regular classes begin again, she will try her hardest to pass all the courses.27._____.

Summer SchoolIt was the first week of June. Gabi just finished her third year of high school. However, when she received her report card in the mail, she learned that she failed a semester of algebra（代数）. _____（26）Gabi was glad she had the chance to make up for the class. She can't move on to the next level in math if she doesn't pass algebra. Summer school isn't easy though. _____（27） During the regular school year, however, she has twenty weeks to do so.Summer school meant that Gabi would be stuck in a hot classroom while most of her friends were at the beach or local amusement parks. Gabi's friends didn't fail any course. _____（28）Going to summer school also meant that Gabi's family had to change their summer vacation plans.Gabi had to be in summer school from 9 a.m. to noon. _____（29）She had to be on the bus at least an hour before class started or else she would be late. The classrooms were hot since the school building was old and did not have air conditioning. When Gabi came home from school, she couldn't do whatever she wanted. She had homework to do.This was the first time Gabi had to go to summer school. _____（30）She made a promise to herself. In the fall, when regular classes begin again, she will try her hardest to pass all the courses.28._____.

Summer SchoolIt was the first week of June. Gabi just finished her third year of high school. However, when she received her report card in the mail, she learned that she failed a semester of algebra（代数）. _____（26）Gabi was glad she had the chance to make up for the class. She can't move on to the next level in math if she doesn't pass algebra. Summer school isn't easy though. _____（27） During the regular school year, however, she has twenty weeks to do so.Summer school meant that Gabi would be stuck in a hot classroom while most of her friends were at the beach or local amusement parks. Gabi's friends didn't fail any course. _____（28）Going to summer school also meant that Gabi's family had to change their summer vacation plans.Gabi had to be in summer school from 9 a.m. to noon. _____（29）She had to be on the bus at least an hour before class started or else she would be late. The classrooms were hot since the school building was old and did not have air conditioning. When Gabi came home from school, she couldn't do whatever she wanted. She had homework to do.This was the first time Gabi had to go to summer school. _____（30）She made a promise to herself. In the fall, when regular classes begin again, she will try her hardest to pass all the courses.29._____.

Summer SchoolIt was the first week of June. Gabi just finished her third year of high school. However, when she received her report card in the mail, she learned that she failed a semester of algebra（代数）. _____（26）Gabi was glad she had the chance to make up for the class. She can't move on to the next level in math if she doesn't pass algebra. Summer school isn't easy though. _____（27） During the regular school year, however, she has twenty weeks to do so.Summer school meant that Gabi would be stuck in a hot classroom while most of her friends were at the beach or local amusement parks. Gabi's friends didn't fail any course. _____（28）Going to summer school also meant that Gabi's family had to change their summer vacation plans.Gabi had to be in summer school from 9 a.m. to noon. _____（29）She had to be on the bus at least an hour before class started or else she would be late. The classrooms were hot since the school building was old and did not have air conditioning. When Gabi came home from school, she couldn't do whatever she wanted. She had homework to do.This was the first time Gabi had to go to summer school. _____（30）She made a promise to herself. In the fall, when regular classes begin again, she will try her hardest to pass all the courses.30._____.

Myths of Our Finger-nailsEveryone knows your finger-nails can show whether you are in good health or not. But that is not entirely true. Well, _____（31）, there are plenty of people with health _____（32）who have normal-looking nails.There can be a significant number of ways that finger-nails of healthy people can look _____（33）. So while paying attention to changes in your nails is_____（34）, thinking that there is a health problem may be too early.Some women _____（35）that rubbing garlic（大蒜）on their nails has helped their nails grow longer. But that is not the case. Keeping nails _____（36）wet in proper ways can help _____（37）them from breaking, particularly in the _____（38）and winter months. It is a good idea to _____（39）hand cream on your hands and finger-nails after washing them, which will offer _____（40）from bad weather.A. differentB. hopefullyC. preventD. believeE. actuallyF. protectionG. valuableH. beautifulI. useJ. issuesK. autumnL. slightly