新疆是我国领土不可分割的一部分。新疆隶属于我国中央政府的管辖开始于( )
A:丝绸之路的开通
B:西域都护的设立
C:三国鼎立局面的形成
D:秦统一六国
①Do you like the red hat? ____ A. He is under the tree.
②Where's the old man? ____ B. No, they aren't.
③How is the lion? ____ C. No, I don't.
④Are they tigers? ____ D. Yes, it is.
⑤Is this a kite?____ E. It is very strong.
将长为1 m的导线ac从中点b折成如图所示的形状,放入B=0.08 T的匀强磁场中,abc平面与磁场垂直.若在导线abc中通入25 A的直流电,则整个导线所受安培力大小为
____ N.
360÷6=____
920÷10=____
720÷80=____