如图所示的装置中,不计滑轮摩擦,当水平向右拉力F=5N时,物体m恰能匀速运动,那么物体受地面的摩擦力的大小为()。
A.5N
B.2.5N
C.10N
D.7.5N
参考答案:B
某男,18岁,平时多汗,活动或进食则大汗出,夜间睡时亦常汗出,此因()。
A.气虚
B.阴虚
C.血虚
D.阳虚
E.气阴两虚
The highway has been closed because of the heavy snow. Please find an ________ means of transport.
A.addictive
B.active
C.attractive
D.alternative