问题
选择题
选用一种试剂就可以一次把物质的量浓度相同的Na2SO4、Na2SO3、Na2CO3、Na2S、BaCl2五种无色溶液加以区别，这种试剂是
A．CaCl2
B．Ba(OH)2
C．H2SO4
D．HCI
答案
答案：C
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选用一种试剂就可以一次把物质的量浓度相同的Na2SO4、Na2SO3、Na2CO3、Na2S、BaCl2五种无色溶液加以区别，这种试剂是
A．CaCl2
B．Ba(OH)2
C．H2SO4
D．HCI
答案：C
Three 21 ago, my family got our first computer. 22 the beginning of this summer, I found it was too old and I wanted to get a 23 one. After my father. and I talked for a long time, he 24 . We went to many shops and read many ads. 25 we bought an HP computer. During the first week, I noticed 26 our computer had some problems. I spent many hours 27 to fix it, but it 28 work. So I 29 to phone the HP company and ask them 30 to work out my problem. They told me to wait until the next morning because all their workers were 31 that day. The next morning two workers came. It took them many hours to mend it, but the computer 32 did not work. My dad had no other way but to return the whole thing. A few days later, we decided that I should go on the Internet and order some parts to build a new computer by 33 . It was not an easy job for me to build a new computer. I tried many times, and in the end I was successful. From these setbacks(挫折), I have learned a lot. Now I believe that if the HP computer hadn't had any problems, 34 I would not have learned how to build the new one. Even though I spent lots of time on it, I know it wasn't 35 .
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