CO和 CO2性质差异很大,将两种气体分别进行下列实验操作,不能区别它们的是( )
A:
B:
C:
D:
— Well, it's hard to say, probably great, or maybe not.
The computer company just released an ____ (更新) version last week, and it'll be used in over 50 local classrooms this coming school year.
在我们周围,可能有这样一群人,他们形影不离,一到下课时间,就在教室里追逐打闹、乱扔课本,上课还经常交头接耳,影响同学们听课,他们的所作所为引起了同学们的强烈不满。对此,下列认识正确的是( )