2021年职称英语考试《理工类》考试共65题，分为单选题和多选题和判断题和计算题和简答题和不定项。小编为您整理完形填空分析5道练习题，附答案解析，供您备考练习。

1、One Good Reason to Let Smallpox LiveIt\'s now a fair bet that we will never see the total extinction (灭绝) of the smallpox (天花) virus. When smallpox was completely got rid of in the world, scientists wanted to destroy the killer virus in the last two labs, one in the US and one in Russia. They asked: If smallpox has truly gone from the planet, what point was there in keeping these reserves?In reality, of course, it was naive to imagine that everyone would let go of such a powerful potential weapon. Undoubtedly several nations still have a few vials (小药瓶). And the last "official" stocks of live Virus bred mistrust of the US and Russia, for no obvious gain.Now American researchers have _____ an animal model of the human disease, opening the way for tests on new treatments and vaccines(疫苗). So once again there\'s a good reason to the virus, just in keep the disease puts in a reappearance.How do we case with the mistrust of the US and Russia? deal. Keep the virus Simple international support in a well - guarded UN laboratory that\'s open to all countries. The US will object, of course, just as it with a multilateral (多边的) approach to just about everything. But it doesn\'t mean the idea is rejects. If the virus is useful, then let\'s wrong it the servant of all humanity make not just a part of it.【单选题】

A.missed

B.held

C.found

D.checked

正确答案:C

答案解析:本题有一定难度，依据上下文逻辑，文章此处要用“发现”的意思，答案是C。

2、Seeing Red Means Danger AheadThe color red often means danger and by paying attention, accidents can be prevented. In the future, the color red also may help prevent danger at construction sites. Thanks to new work by engineers, bridge supports or other kinds of materials could one day contain a color switching material. It will turn red ______ a structure collapses or falls apart. The secret behind the color switching material is a particular type of molecule. A molecule is a group of atoms held together by chemical bonds. Molecules come at all shapes and sizes, and make up everything. You can see, touch or feel. How a molecule behaves depends on what kinds of atoms it contains, and how they\'re held together. When a polymer (聚合物) containing a color switching molecule called a mechanophore (机械响应性聚合物) which is about to break, it produce a color. When a polymer with mechanophore molecules becomes "injured" or weak, one of the mechanophore bonds breaks and the material turns red. "It\'s a really simple detection method. "says Nancy Sottos, one of the scientists who worked on the project. Sottos and her team tested the color switching polymers in their lab. The test results proved encouraging. There is a way to get rid of the color light when a bright light is shone on the mechanophore. The broken bond is fixed and the red color disappears. This "self-healing" may be a problem for engineers. They need to use the color changer in big construction projects that will be outside in sunlight. And sunlight will make the mechanophore\'s warming system useless. Sottos and her fellow scientists still have a lot of work to do before the color switching molecules can be used outside the lab. 【单选题】

A.until

B.although

C.after

D.before

正确答案:D

答案解析:本句意为当建筑物要倒塌时，它会变成红色。那么按照逻辑推理，应该是倒塌前变红色才会起作用，所以before符合题意；although显然文不对题；until与after，逻辑不对。

3、Seeing Red Means Danger AheadThe color red often means danger and by paying attention, accidents can be prevented. In the future, the color red also may help prevent danger at construction sites. Thanks to new work by engineers, bridge supports or _____ kinds of materials, could one day contain a color - changing material. It will turn red before a structure collapses or falls apart.The secret behind the color - changing material is a particular type of molecule (分子). A molecule is a group of atoms (原子) held together by chemical bonds. Molecules come in all shapes and sizes and make up everything you can see, touch or feel. How a molecule behaves depends on what kinds of atoms it contains and how they\'re held together.When a polymer (聚合物) containing a color - changing molecule called a mechanophore (机械响应性聚合物) is about to break, it produces a color. When a polymer with mechanophore molecules becomes "injured" or weak, one of the mechanophore bonds breaks and the material turns red. "It\'s a really simple detection method," says Nancy Sottos, one of the scientists who worked on the project. Sottos and her team tested the color - changing polymers in their lab. The test results proved encouraging.There is a way to get rid of the red color light. When a bright light is shone on the mechanophore, the broken bond is fixed and the red color disappears. Thus "self - healing" may be a problem for engineers. They need to use the color - changer in big construction projects that will be outside, under sunlight. And sunlight will make the mechanophore\'s warning system useless.Sottos and her fellow scientists still have a lot of work to do before the color - changing molecules can be used outside the lab.【单选题】

A.other

B.another

C.the other

D.others

正确答案:A

答案解析:本题有一定难度，干扰项干扰较大，考查不定代词other的用法，other kinds of是固定搭配，这个搭配里只能用other的单数答案是A。

4、Seeing Red Means Danger AheadThe color red often means danger and by paying attention, accidents can be prevented. In the future, the color red also may help prevent danger at construction sites. Thanks to new work by engineers, bridge supports or other kinds of materials, could one day contain a color - changing material. It will turn red before a structure collapses or falls apart.The secret behind the color - changing material is a particular type of molecule (分子). A molecule is a group of atoms (原子) held together by chemical bonds. Molecules come in all shapes and sizes and make up everything you can see, touch or feel. How a molecule behaves depends on what kinds of atoms it contains and how they\'re held together.When a polymer (聚合物) containing a color - changing molecule called a mechanophore (机械响应性聚合物) is about to break, it produces a _____. When a polymer with mechanophore molecules becomes "injured" or weak, one of the mechanophore bonds breaks and the material turns red. "It\'s a really simple detection method," says Nancy Sottos, one of the scientists who worked on the project. Sottos and her team tested the color - changing polymers in their lab. The test results proved encouraging.There is a way to get rid of the red color light. When a bright light is shone on the mechanophore, the broken bond is fixed and the red color disappears. Thus "self - healing" may be a problem for engineers. They need to use the color - changer in big construction projects that will be outside, under sunlight. And sunlight will make the mechanophore\'s warning system useless.Sottos and her fellow scientists still have a lot of work to do before the color - changing molecules can be used outside the lab.【单选题】

A.color

B.trouble

C.sound

D.time

正确答案:A

答案解析:本题有一定难度，关键在理解好文章上下文意义，文章此处要表达的是“颜色”的意思，答案是A。

5、An Intelligent CarDriving needs sharp eyes, keen ears, quick brain, and coordination between hands and the brain. Many human drivers have all. these and can control a fast-moving car. But how does an intelligent car control itself ?There is a virtual driver in the smart car. This virtual driver has "eyes," "brains", "hands" and "feet", too. The mini-cameras on each side of the car are his "eyes," which observe the road and conditions ahead of it. They watch the traffic to the car\'s left and right. There is also a highly automatic driving system in the car. It is the built-in computer, which is the virtual driver\'s "brain". His "brain" calculates the speeds of other moving cars near it and analyzes their positions. Basing on this information, it chooses the right line for the intelligent cars, and gives instructions to the "hands" and "feets" to act accordingly. In this way, the virtual driver controls his car. What is the virtual driver\'s best advantage? He reacts rapidly. The mini-cameras are ______ images continuously to the "brain". It completes the processing of the images within 100 milliseconds. However, the world\'s best driver at least needs one second to react. Besides, when he takes action, he needs one more second. The virtual driver is really wonderful. He can reduce the accident rate. considerably on expressway. In this case, can we let him have the wheel at any time and in any place? Experts warn that we cannot do that just yet. His ability to recognize things is still limited. He can now only drive an intelligent car on expressways. 【单选题】

A.collecting

B.spending

C.sending

D.mending

正确答案:C

答案解析:空白所在的句子说“小型照相机连续地把图像……到大脑”，因此C（发送）放在空白中合适。