I _____play tennis,but I play table tennis.
A:can;can't
B:can;can
C:can't;can't
D:am;can't
为了测量某一电线杆的高度,简单实际的办法是( )
–No, she didn't. But she _______ us for dinner.
根据比与除法和分数的关系,我们可以灵活地解决问题.
比的前项=____ ×比值
比的后项=____________ .