测定砂有机物含量的试验试剂主要有（）。
A.氢氧化钠
B.乙醇
C.蒸馏水
D.鞣酸
E.盐酸
参考答案：A, B, C, D
--Liu Xiang had to give up the race because of his foot.
--_________
A. What a shame! B. Of course. C. He was so careless.
句型转换
1. He has 5 volleyballs.(改为否定句)
_____________________________
2. I have a baseball bat.(改为一般疑问句)
3. She plays sports every day.
(改为一般疑问句，并做否定回答)
4. Do you have tennis rackets?(将主语改为he)
