The magic show has been on 20 minutes. It has been on 2.p.m.
A:for, since
B:in, since
C:for, for
D:since, for
如图所示,小物体A与圆盘保持相对静止跟着圆盘一起做匀速圆周运动,则A受力情况是( )
据报道,中国正在研制的大推力运载火箭“长征五号”有望于2014年后发射月球车、大卫星和空间站,若“长征五号”燃料燃烧只有水生成,则应选用的燃料是( )
按拼音写汉字
cháng é
gūi lì
xuàn làn
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