单项选择题
A.10%~20% B.15%~20% C.10%~25% D.10%~15% E.15%~25%
A.8周 B.6周 C.5周 D.2周 E.3周
A.肾脏 B.大脑 C.乳腺 D.下丘脑 E.肝脏