美卡拉明主要阻断（）
A．β受体
B．α受体
C．N2胆碱受体
D．N1胆碱受体
E．M胆碱受体
参考答案：D
Which sentence is wrong?
A．We don’t think it necessary to give students tests every week.
B．We don’t have to worry about not having enough to eat now.
C．My father has left school for over twenty years.
D．He was heard singing a pop song when I passed his room.
顶针
