如果贝克曼重排反应后（）中SO3含量为4%便说明SO3的供给量是充足的。
A、发烟硫酸
B、环己酮肟
C、重排混合物
D、氨水
参考答案：C
—Hello, Mike. Where is our teacher?
—Oh, he _______ the library. He'll be back in a minute.[ ]
A. has gone to
B. has been to
C. went
D. will go
肝性脑病前驱期的临床表现有（）
A.可有扑翼样震颤
B.昏睡
C.定向力减退
D.脑电图异常
E.计算力下降
