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 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. ______, 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.Generally

B.Surprisingly

C.Disappointedly

D.Shortly

正确答案:B

答案解析:最后一段的第一和第二句告诉我们手机经过清洗后仍然有微量DNA出现。所以这里要用surprising这个副词，表示令人惊讶。

2、Breastfeeding Can Cut Cardiovascular Risk
Breastfeeding can reduce the risk of a heart attack or stroke later in life and could prevent hundreds of thousands of deaths each year, researchers said on Friday.
Babies who are breastfed have fewer childhood infections and allergies and are less prone to obesity. British scientists have now shown that breastfeeding and slow growth in the first weeks and months of life has a protective effect against cardiovascular disease.
"Diets that promote more rapid growth put babies at risk many years later in terms of raising their blood pressure, raising their cholesterol and increasing their tendency to diabetes and obesity-the ______ main risk factors for stroke and heart attack." said Professor Alan Lucas of the Institute of Child Health in London.
"Our evidence suggests that the reason why breast-fed babies do better is because they grow more slowly in the early weeks."
Lucas said the effects of breastfeeding on blood pressure and cholesterol later in life are greater than anything adults can do to control the risk factors for cardiovascular disease, other than taking drugs.
An estimated 17 million people die of cardiovascular disease, particularly heart attack and strokes, each year, according to the World Health Organization.
Lucas and his colleagues compared the health of 216 teenagers who as babies had either been breastfed or given different nutritional baby formulas' They reported their findings in The Lancet medical journal.
The teenagers who had been breastfed had a 14 percent lower ratio of bad to good cholesterol and lower concentrations of a protein that is a marker for cardiovascular disease risk.
The researchers also found that regardless of the child's weight at birth, the faster the infants grew in the early weeks and months of life, the greater was their later risk of heart disease and stroke. The effect was the same for both boys and girls.
"The more human milk you have in the newborn period, the lower your cholesterol level is, the lower your blood pressure is 16 years later, "Lucas said.
【单选题】

A.two

B.four

C.three

D.five

正确答案:B

答案解析:前句中先后提到了血压、胆固醇、糖尿病和肥胖，共计4项。

3、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 switching material. It will turn red before 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 ______. 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.repairs

B.controls

C.finishes

D.disappears

正确答案:D

答案解析:前文说断裂的联系从新凝合，那么红色相对应的，就应是消失、褪去。

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 switching material. It will turn red before 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 ______ 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.inside

B.beside

C.outside

D.above

正确答案:C

答案解析:后文有in sunlight，理解为材料暴露在太阳之下，选outside。

5、One Good Reason to Let Smallpox Live
It'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 found 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 _____ not just a part of it.
【单选题】

A.take

B.do

C.make

D.ask

正确答案:C

答案解析:本题有一定难度，考查动词make的用法，指“使……成为”，后面接双宾语，make it the servant，文章此处是说“如果病毒有用，就让它成为人类的服务者……”，答案是C。