用80N的力将重为30N的重物压在竖直墙壁上，重物在墙上刚好匀速下滑，则重物受到

在如图所示的电路中，圈①、②、③处可以接小灯、电流表或电压表（均为理想电表）三种元器件，电源电动势E、内阻r均保持不变，定值电阻R₁:R₂:R₃:R₄＝4:3:2:1，小灯电阻R_L＝R₁，R₁＞r，电路中有电流通过，下列说法中正确的是

A．要使路端电压最大，则应该①接小灯，②接电压表，③接电流表

B．要使电源输出功率最大，则应该①接电流表，②接小灯，③接电压表

C．要使电源总功率最大，则应该①接电流表，②接电压表，③接小灯

D．要使闭合电路中电源效率最高，则应该①接小灯，②接电流表，③接电压表

— How far apart do they live? 

— _____ I know, they live in the same neighbourhood. [ ]

A. As long as

B. As far as

C. As well as

D. As often as

“弟子不必不如师，师不必贤于弟子，闻道有先后，术业有专攻，如是而已”这种观点给当今教育的启示是( )

A．教学相长。相互尊重

B．乐教善教，讲究教法

C．严于律己，为人师表

D．有教元类，教书育人

基本图包括______、______、______、______、______、______和______。详图包括______、______和______。

A: May I see your driver’s license and vehicle registration card, please
B: ().

A. Sorry, don’t write me a ticket.

B. Ok. But I was driving at 65 miles per hour.

C. Sure. Did I do anything wrong

D. Yes. But I don’t think I’m a bad driver.