一包白色粉末可能由碳酸钠、硫酸钠和氯化钠中的2种或3种组成.经实验得知其中肯定含

题型:问答题

问题:

一包白色粉末可能由碳酸钠、硫酸钠和氯化钠中的2种或3种组成.经实验得知其中肯定含有碳酸钠和硫酸钠.为了确定是否含有氯化钠,某同学设计了以下实验.请该同学的思路填写下表:

实验操作步骤实验目的、现象及结论
(1)取少量白色固体粉末,配成水溶液,向其中加入足量的稀酸A,A为_______除去_________________________
(2)继续加入足量的B,B为_______除去硫酸钠
(3)向(2)中的滤液中加入C,C为___溶液若有_________,证明原白色固体粉末中肯定含有氯化钠;否则不含氯化钠

考点:酸的性质盐的性质物质的除杂物质的鉴别物质的推断
题型:问答题

What should you think about in trying to find your career? You are probably better at some school subjects than others.   小题1:  A boy who is good at mathematics can use that in an engineering career.   小题2:  So it is important to do well at school. On the other hand, you may not have any specially strong or weak subjects but your records show a general satisfactory standard. __小题3:  Knowledge of history is not required for most jobs but if history is one of your good subjects you will have learned to remember facts and details. This is an ability that can be useful in many jobs.

 小题4: If nothing else, you may have learned how to get to work on time, to follow instructions and to get on with older workers. Just as important, you may become interested in a particular industry or career you see from the inside in a part-time job.

Facing your weak points is also part of knowing yourself.  小题5: Your school record, for instance, may not be too good, yet it is an important part of your background. You should not be apologetic about it but instead recognize that you will have a chance of a fresh start at work.

A.He may do well in his future work.

B.It is bitter to face any weaknesses than to pretend they do not exist.

C.Although not all subjects can be used directly in a job, they may have indirect value.

D.These may show strengths that you can use in your work.E. Your school must have taught you the skills.

F. A girl who spells well and likes English may be good at office work.

G. If you have had a part-time job on Saturday or in the summer, think what you gained from it.

题型:问答题

杀灭畜体内线虫和外寄生虫的有效药物是()

A.溴氰菊酯

B.左旋咪唑

C.伊维菌素

D.强力霉素

E.硝氯酚

题型:问答题

试分析“不同结构化程度的教育活动组成的连续体”的涵义及对课程和教育活动设计和实施的启示。

题型:问答题

哪些是热射病特征性临床表现()

A.高热

B.无汗

C.头痛

D.骨骼肌痉挛

E.意识障碍

题型:问答题

根据直流泄漏电流测量值及其施加的直流试验电压值,可以换算出试品的绝缘电阻值。()

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