主疏泄的脏是()
A.肝
B.心
C.脾
D.肺
E.肾
参考答案:A
You'd better _____ outside. It's raining.[ ]
A. go
B. not go
C. not going
D. don't go
基因型是YyRR的植物,其自交后代表现型的比例为 [ ]
A.3:1
B.1:1:1:1
C.1:2:1
D.9:3:3:1