题干

某同学鉴别NH4HCO3、NH4Cl、KCl三种化肥的过程如图,其中,试剂甲和乙分别是(  )


A:甲:NaCl溶液    乙:稀盐酸

B:甲:NaOH溶液    乙:稀盐酸

C:甲:水    乙:NaOH溶液

D:甲:稀盐酸     乙:NaCl溶液

上一题 下一题 0.0难度 选择题 更新时间:2015-12-17 10:38:46

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。

        Maybe you are an average student.You probably think you will never be a top student. This is not necessarily so,however. Anyone can become a better student if he or she wants to. Here's how:

____When planning your work, you should make a list of things that you have to do. After making this list, you shouldmake a schedule of your time. First your time for eating, sleeping, dressing,etc.Then decide a good, regular time for studying.____A weekly schedule may not solve all your problems, but it will force you to realize what is happening to your time.

        Find a good place to study. Look around the house for a good study area.Keep this space, which may be a desk or simply a corner of your room, free of everything but study materials. No games, radios,or television. When you sit down to study, concentrate on the subject.

        Make good use of your time in class.____Listening carefully in class meansless work later. Taking notes will help you remember what the teacher says.

        Study regularly. When you get home from school, go over your notes, review the important points that your teacher is going to discuss the next day, read that material.____If you do these things regularly, the material will become more meaningful, and you'll remember it longer.

        Develop a good attitude towards tests.The purpose of a test is to show what you have learned about a subject. They help you remember your new knowledge.The world won't end if you don't pass a test, so don't be over­worried.

____Youwill probably discover them after you have tried these.

A.There are other methods that might help you with your studying.

B.Don't forget to set aside enough time for entertainment.

C.Take advantage of class time to listen to everything the teacher says.

D.No one can become a top student unles she or she works hard.

E.Plan your time carefully.

F.Make full use of class time to take notes of what the teacher says in class.

G.This will help you understand the nextclass.