A. You're welcome.
B. What shape would you like?
C. I'd like some cherries, too.
D. What kind of pudding would you like?
E. Yes. I want to buy a pudding.
A: Can I help you?
B:____
A:____
B: I'd like a chocolate pudding.
B: I'd like a heart-shaped pudding.
A: Anything else?
B:____How much are they?
A: 70 yuan.
B: Here is the money.
A: Thank you.
如图,已知⊙O1的半径为1cm,⊙O2的半径为2cm,将⊙O1,⊙O2放置在直线l上,如果⊙O1在直线l上任意滚动,那么圆心距O1O2的长不可能是( )
2014年10月24日,“嫦娥五号”探路兵发射升空,为计划于2017年左右发射的“嫦娥五号”探路,并在8天后以“跳跃式返回技术”成功返回地面.“跳跃式返回技术”指航天器在关闭发动机后进入大气层,依靠大气升力再次冲出大气层,降低速度后再进入大气层.如图所示,虚线为大气层的边界.已知地球半径R,地心到d点距离r,地球表面重力加速度为g.下列说法正确的是( )