外来化合物的概念是( )
A.存在于人类生活和外界环境中
B.具有生物活性,并有损害作用
C.与人类接触并进入机体
D.以上都正确
E.以上都错误
参考答案:D
—Did you see who the driver was?
— No, so quickly _____ that I couldn’t get a good look at his face.
A.does the car speed by
B.did the car speed by
C.the car sped by
D.the car speeds by
重症肌无力患者出现胆碱能危象时表现为()
A.瞳孔缩小、分泌物增多
B.腹痛、腹泻、汗多
C.肌束颤动
D.高热,血压降低
E.呼吸肌无力