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。小编每天为您准备了5道每日一练题目（附答案解析），一步一步陪你备考，每一次练习的成功，都会淋漓尽致的反映在分数上。一起加油前行。

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 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 _____ 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.results

B.rules

C.tools

D.methods

正确答案:A

答案解析:本题难度不大，考查的是词义辨析。很明显，文章此处的意思是“结果”，答案是A。

2、The minimum age of Chinese citizens who are eligible to vote is eighteen. 【单选题】

A.encouraged

B.enforced

C.entitled

D.expected

正确答案:C

答案解析:encouraged:被鼓励的、受到鼓舞的；enforced:受强迫的、被迫的；entitled:授权的、有资格的，和句子中的eligible意思相同；expected：受到期待的、被期望的、所预期的。

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 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 _____ 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.why

B.how

C.what

D.where

正确答案:C

答案解析:本题难度不大，考查宾语从句引导词what的用法，本题可以先看选项，得到信息提示，很明显，答案是C。

4、A number of theories have been proposed to explain the situation.【单选题】

A.suggested

B.tested

C.used

D.announced

正确答案:A

答案解析:有多种理论被建议用来解释目前形势。本题难度不大，干扰项干扰性不大，propose和suggest都有“建议”的意思，最佳答案是A。

5、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 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 ______ 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.results

B.rules

C.tools

D.methods

正确答案:A

答案解析:本句意为其实验结果令人振奋，所以应选results。