风媒花的主要特点有（）。
A.花被小
B.花被鲜艳
C.无香味
D.花粉粒小
参考答案：A, C, D
惊厥的原因是
A．支气管肺炎B．败血症C．手足搐搦症D．低血糖E．癫痫
There are five people in the room, but I know . [ ]
A. both of them
B. none of them
C. all of them
D. neither of them
