内科腹痛的临床特点有（）
A．先发热后腹痛
B．先腹痛后发热
C．痛无定处
D．压痛明显
E．压痛不明显
参考答案：A, C, E
Since I came to China I've known that about seven people _____ ten speak Chinese. [ ]
A. of
B. to
C. in
D. about
在2千克盐水中，盐和水的比是1：9，盐有______，含盐率是______%．
