We don't think it's good to stay_____ late to play computer games.
A:on
B:up
C:from
D:out of
将下列陈述句改成反问句
①那奔驰的列车正是我们祖国奋勇前进的象征。
②都是你自己找的,我帮不得了你的忙。
下列关于生物生殖和发育的叙述,正确的是( )