A:making
B:causing
C:catching
D:Putting
某兴趣小组借助无人飞机航拍校园.如图,无人飞机从A处水平飞行至B处需8秒,在地面C处同一方向上分别测得A处的仰角为75°,B处的仰角为30°.已知无人飞机的飞行速度为4米/秒,求这架无人飞机的飞行高度.(结果保留根号)
Mum:Mary. ____
Mary:It's very pretty.
Assistant: ____
Mum:Yes. ____
Assistant:It's $ 99.
Mum:Oh, that's expensive.
Assistant:Do you like that blue skirt?
Mary:Yes. ____
Mum:OK. How much is it?
Assistant:It's $ 50.
Mum: ____
A. Can I help you?
B. OK. I'll take it.
C. How do you like this dress?
D. I like blue.
E. How much is it?
在列宁的领导下,1921年苏俄开始实施新经济政策。新经济政策的实施促进了国民经济的恢复和发展,同时也加快了实现农业集体化的步伐。( )