题干

分泌蛋白是在细胞内合成后,分泌到细胞外起作用的一类蛋白质。原核细胞形成分泌蛋白与真核细胞形成分泌蛋白的相同点是

A:合成蛋白质的主要场所都是内质网上的核糖体

B:合成蛋白质的过程都是由染色体上的基因控制

C:合成蛋白质时都有细胞核内的转录

D:分泌蛋白质时都要依靠细胞膜的流动性

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答案(点此获取答案解析)

D

同类题2

根据短文内容,从A、B、C、D四个选项中选出一个能填入相应空格内的最佳答案。

    Tom worked hard in an office. But it seemed that there was little change in his life. He was unhappy and didn't want to improve himself any more. His father, Joe, knew this and decided to have a talk with 1 .

    One day, Tom and his father went for a walk after dinner. 2 they were walking along a river, Tom said, “Dad, you always tell me to learn something new. To be3, I don't want to make any change.”

    Joe looked in the river, saw a dead 4and pointed at it.

    “Tom, what is that over there?”

    “It's a dead fish.”

    “What's the fish doing?”

    “It's moving down with the running water.”

    “But the fish is dead. 5 can it be moving?” asked Joe.

    “It's moving as the river is moving.”

    Joe turned to his son and said, “Life is 6 the river. It's always moving and always changing. Some people don't want to change, but their life is always changing whether they like it or not. A dead fish only moves along the river, while a living fish can control its journey. What's your choice if you want to live a 7 life?”

    This made Tom 8 his aunt who had already stopped learning and developing. And she just stayed the way she used to be, living like a dead fish.

    Guided by his 9 , Tom understood what he said. He didn't want to become a person like his aunt. So he made up his mind to 10  learning and developing himself.

同类题5

任务型阅读

    If you are like most international students, you are probably pretty comfortable reading and writing in English. ____Below are some tips to help you to improve your conversational skills.

    Make friends with American students. Many international students end up making friends with a lot of—or only—other international students.____ Hanging out with natives not only naturally pushes you to improve your spoken English, but also helps you pick up cultural and social information.

    Learn from American friends. Tell your American friends that you are trying to improve your listening and speaking skills, and would like them to help you. If you pronounce a word incorrectly, or misuse an idiom, you ask them to guide you. ____

    Increase your knowledge. ____ If you have been exposed to topics that are likely to be discussed in conversation, you have a much better chance of understanding people when they talk, and of being able to express yourself well.

    ____ If you have to explain something to someone, you have a strong motivation to pronounce everything as well as you can, and find other ways to explain yourself. Finally, this becomes a good habit. Many people have asked me how I learned to speak English fluently, and I owe most of it to my years of being a math teacher in college for years.

A. It is bad for them to do that.

B. You will make progress this way.

C. If possible, become a teacher at your school.

D. It's a win-win opportunity for international students.

E. Keep up with news and watch popular shows and movies.

F. Explaining everything in a different way counts.

G. You may have trouble in listening and speaking in the language, however.