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、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 _____ 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.on

B.behind

C.under

D.down

正确答案:B

答案解析:本题有一定难度，干扰项干扰较大，考查介词behind的用法，文章此处是说，“材料颜色可以变化其背后的秘密是……”，只有behind可以表示“背后的”意思，答案是B。

2、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 ______ 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 sending 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.police

B.traffic

C.trucks

D.buses

正确答案:B

答案解析:空白所在的句子说“它们观察智能车左右两侧的…”，B（车流）放入空白处最恰当。

3、Cell Phone Lets Your Secret OutYour cell phone holds secrets about you. Besides the names and numbers that you\'ve programmed into it, traces of your DNA linger on the device, according to a new study.DNA is genetic material that appears in every cell. Like your fingerprint, your DNA is unique to you- ______ you have an identical twin. Scientists today routinely analyze DNA in blood, saliva, or hair left behind at the scene of a crime. The results often help detectives identify criminals and their victims. Your cell phone can reveal more about you than you might think.Meghan J. McFadden, a scientist at McMaster University in Hamilton, Ontario, heard about a crime in which the suspect bled onto a cell phone and later dropped the device. This made her wonder whether traces of DNA lingered on cell phones even when no blood was involved. So she and colleague Margaret Wallace of the City University of New York analyzed the flip open phones of 10 volunteers. They used swabs to collect invisible traces of the users from two parts of the phone: the outside, where the user holds it, and the speaker, which is placed at the user\'s ear.The scientists scrubbed the phones using a solution made mostly of alcohol. The aim of washing was to remove all detectable traces of DNA. The owners got their phones back for another week. Then the researchers collected the phones and repeated the swabbing of each phone once more.The scientists discovered DNA that belonged to the phone\'s speaker on each of the phones. Better samples were collected from the outside of each phone, those swabs also picked up DNA that belonged to other people who had apparently also handled the phone. Surprisingly, DNA showed up even in swabs that were taken immediately after the phones were scrubbed. That suggests that washing won\'t remove all traces of evidence from a criminal\'s device. So cell phones can now be added to the list of clues that can clinch a crime scene investigation.【单选题】

A.because

B.unless

C.although

D.still

正确答案:B

答案解析:上文的意思是：如同指纹，你的DNA是独一无二的。因此，此处必须选择unless，其他选择均不符合句义，也违背了我们对DNA的基本常识。

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 color. When a polymer with mechanophore molecules becomes "injured" or _____, 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.strong

B.soft

C.weak

D.hard

正确答案:C

答案解析:本题有一定难度，关键在理解好文章上下文意义，文章此处的or表明后面用词要和injured相近，答案是C。

5、Animal\'s "Sixth Sense"A tsunami was triggered by an earthquake in the Indian Ocean in December, 2004. It killed tens of thousands of people in Asia and East Africa, Wild animals, however, seem to have escaped that terrible tsunami. This phenomenon adds weight to notions that they possess a "sixth sense" for disasters, experts said.Sri Lankan Wildlife officials have said the giant waves that killed over 24,000 people along the Indian Ocean island\'s coast clearly missed wild beasts, with no dead animals found."No elephants are dead, not even a dead rabbit. I think animals can sense disaster. They have a sixth sense. They know when things are happening" H. D. Ratnayake, deputy director of Sri Lanka\'s Wildlife Department, said about one month after the tsunami attack. The ______ washed floodwaters up to 2 miles inland at Yala National Park in the ravaged southeast, Sri Lanka\'s biggest wildlife reserve and home to hundreds of wild elephants and several leopards."There has been a lot of scientific evidence about dogs barking or birds migrating before volcanic eruptions or earthquakes. But it has not been proven," said Matthew van Lierop, an animal behavior assistant at Johannesburg Zoo. "There have been no specialist studies because you can\'t really test it in a lab or field setting," he told Reuters. Other authorities concurred with this assessmetn."Wildlife seem to be able to pick up certain phenmenon, especially birds. There are many reports of birds detecting impending disasters," said Clive Walker, who has written several books on African wildlife.Animals certainly rely on the known senses such as smell or hearing to avoid danger such as predators. The notion of an animal "sixth sense" -or some other mythical power-is an enduring one which the evidence on Sri Lanka\'s ravaged coast is likely to add to. The Romans saw owls as omens of impending disaster and many ancient cultures viewed elephants as sacred animals endowed with special powers or attributes.【单选题】

A.waves

B.tides

C.winds

D.rivers

正确答案:A

答案解析:本句说的是海的巨浪将洪水带到离海岸远超2英里的东南部内陆Yala国家公园。正确答案应该是waves。