A:what
B:which
C:how
D:where
下列选项中,两类细胞的染色体数目均可呈周期性变化的是( )
— __________. That man got his books and left a few minutes ago.
关于秦岭-淮河一线的叙述,不正确的是:
幅画按1:2复印出来。