—Children today find it hard to focus on study.
—Exactly,as they________so many fun things to do.
A:found
B:have found
C:had found
D:will find
陆地面积占全球面积的( )
消化系统中,不与食物直接接触的器官是( )
请将A,B,C三种动物与它们的幼虫(D,E,F)配对起来:
A ____ D
B ____ E
C ____ F