2019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、Cell Phone Lets Your Secret Out
Your 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- because 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 ______ 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.upon

B.back

C.without

D.with

正确答案:B

答案解析:根据上下文的理解，应该选择back：手机拥有者拿回了手机，再使用一个星期。

2、Better Control of TB Seen if a Faster Cure is Found
The World Health Organization estimates that about one-third of all people are infected with bacteria that cause tuberculosis. Most times, the infection remains inactive. But each year about eight million people develop active cases of TB, usually in their lungs. Two million people die of it. The disease has increased with the spread of AIDS and drug-resistant forms of tuberculosis.
Current treatments take at least six months. Patients have to take a combination of several antibiotic drugs daily. But many people stop ______ they feel better. Doing that can lead to an infection that resists treatment. Public health experts agree that a faster-acting cure for tuberculosis would be more effective. Now a study estimates just how effective it might be. A professor of international health at Harvard University led the study. Joshua Salomon says a shorter treatment program would likely mean not just more patients cured. It would also mean fewer infectious patients who can pass on their infection to others.
The researchers developed a mathematical model to examine the effects of a two-month treatment plan. They tested the model with current TB conditions in Southeast Asia. The scientists found that a two-month treatment could prevent about twenty percent of new cases. And it might prevent about twenty-five percent of TB deaths. The model shows that these reductions would take place between two thousand twelve and two thousand thirty. That is, if a faster cure is developed and in wide use by two thousand twelve.
The World Health Organization developed the DOTS program in nineteen ninety. DOTS is Directly Observed Treatment, Short-course. Health workers watch tuberculosis patients take their daily pills to make sure they continue treatment.
Earlier this year, an international partnership of organizations announced a plan to expand the DOTS program. The ten-year plan also aims to finance research into new TB drugs. The four most common drugs used now are more than forty years old. The Global Alliance for TB Drug Development says its long-term goal is a treatment that could work in as few as ten doses.
【单选题】

A.as if

B.as though

C.as far as

D.as soon as

正确答案:D

答案解析:答题时请注意句首的But这个词，与上句意思发生转折。4个选项中as if、as though都是“仿佛，宛如”的意思，as far as则是“至于……，就……而言”的意思，填在这里均不合适，只有as soon as（一……就……）才恰当。

3、An Intelligent Car
Driving 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。

4、Seeing Red Means Danger Ahead
The 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 _____ 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.until

B.although

C.after

D.before

正确答案:D

答案解析:本题有一定难度，干扰项干扰较大，考查介词before的用法，文章此处是说，“它在建筑物倒塌之前会变成红色”，此处要用“之前”的意思，答案是D。

5、Seeing Red Means Danger Ahead
The 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 weak, one of the mechanophore bonds _____ 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.closes

B.breaks

C.increases

D.burns

正确答案:B

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“断开”的意思，答案是B。