— You must have seen the great waterfall there.

— Sure. It is really a wonder, _____ that still seems right in front of me. [ ]

A. one

B. it

C. that

D. which

从胎儿到成人，先后出现两次生长突增高峰，分别为（）。

A.胎儿期

B.胎儿4个月至出生后1年

C.生后第2年

D.2岁后至青春期前

E.青春发育初期