采煤工作面采高超过（）m或片帮严重时，液压支架必须有护帮板，防止片帮伤人。
A、2
B、2.5
C、3
D、3.5
参考答案：C
电子商务的对象是从事以（）为中心的各种商务活动。
A.商品交易
B.商品运输
C.商务营销
D.商业管理
句型转换。
1. What's the matter with you?(改为同义句)
_______ _______with you?
_______ your_______?
2. Let's go to Li I.e i 's house to play computer games. (改为同义句)
_______ not _______ to Li Lei's house to play computer games?
_______we _______ to Li Lei's house to play computer games?
_______ _______ going to Li Lei's house to play computer games?
3. —I'm dizzy (头晕目眩的).
—You should lie down and rest. (改为同义句)
—I'm dizzy (头晕目眩的).
—You should lie down and _______ _______ _______.
