—Could I swim here?
— .Look at the sign NO SWIMMING.
A:No,you couldn't
B:Certainly,you could
C:Sorry,please don't
D:Of course,you can
Put your hands behind your back. Don't speak. We ______ in ten minutes.
已知F1=3N,F2=5N,那么它们的合力大小不可能是
如图2,钟表中9点30分时,时钟的分针与时针所成角的度数为()
读经纬网示意图,完成下列各题: