食用发芽的马铃薯中毒是因为其中含有
A．龙葵素
B．氢氰酸
C．秋水仙碱
D．皂甙
参考答案：A
— Ann is in hospital.
— Oh ,really? I ______ know. I ______ go and visit her.[ ]
A. didn't, am going to
B. don't , would
C. don't, will
D. didn't, will
润滑系的作用不包括（）。
A、清洁
B、润滑
C、传热
D、冷却
