题干

下列说法中,正确的是(  )

A:在紫外线、饱和(NH42SO4溶液、CuSO4溶液、福尔马林等作用下,蛋白质均会发生变性

B:在一定条件下,氨基酸之间能发生反应,合成更复杂的化合物(多肽)

C:为检验皂化反应进行程度,取几滴反应液,滴入装有热水的试管中,震荡,若有油滴浮在液面上,说明油脂已完全反应

D:检验淀粉在稀硫酸催化条件下水解产物的方法是:取适量水解液于试管中,加入少量新制Cu(OH)2悬浊液,加热煮沸,观察是否出现红色沉淀

上一题 下一题 0.0难度 选择题 更新时间:2019-07-09 09:11:04

答案(点此获取答案解析)

B

同类题2

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

    Taking good notes is a time-saving skill that will help you to become a better student in several ways ____.Second, your notes are excellent materials to refer to when you are studying for a test. Third, note-taking offers variety to your study time and helps you to hold your interest.

    You will want to take notes during classroom discussions and while reading a textbook or doing research for a report. ____ Whenever or however you take notes, keep in mind that note-taking is a selective process. ____

    The following methods may work best for you.

●Read the text quickly to find the main facts and ideas in it.

●Carefully read the text and watch for words that can show main points and

supporting facts.

● Write your notes in your own words.

____

● Note any questions or ideas you may have about what was said or written.

    As you take notes, you may want to use your own shorthand(速记). When you do, be sure that you understand your symbols(符号) and that you use them all the time. ____

A.Use words, not complete sentences.

B.There are three practical note-taking methods.

C.You must write your notes on separate paper.

D.Otherwise, you may not be able to read your notes late

E. you will also want to develop your own method for taking notes.

F. That means you must first decide what is important enough to include in your notes.

G. First, the simple act of writing something down makes it easier for you to understand and remember it.