蒸腾作用发生的主要部位是（ ）
A：根
B：叶
C：所有器官
D：茎
zhì
fěi
脍____人口
获益____浅
下列关于体液免疫与细胞免疫的叙述中，正确的是（ ）
— He's never advised to achieve a balance between his job and hobbies, ________? — _______. His parents and teachers often offer him advice.
旅游已经成为现代人比较普遍的休闲方式之一。
