如图，当开关闭合，且将滑动变阻器的滑片P向上移动时，电磁铁将_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

如图，当开关闭合，且将滑动变阻器的滑片P向上移动时，电磁铁将（　　）

A．b端是N极，磁性减弱

B．a端是S极，磁性增强

C．a端是N极，磁性增强

D．b端是S极，磁性减弱

答案

答案：C

选择题

Most scientists seem to agree that ______ certain limit should be set on _______ consumption of cars to ease air pollution.

A．a; the

B．/; the

C．the; /

D．the; the

选择题

— How long do you think it will be _____ China sends a manned spaceship to the moon?
— Perhaps two or three years.

A. when
B. until
C. that
D. before