社团组织的根本特征是（）。
A.劳动分工所致
B.同类相聚而成
C.领袖人物组织形成
D.按阶级阶层划分而成
参考答案：B
We went to the West Lake yesterday, _______, not surprisingly, was crowded with visitors from all
over the world. [ ]
A. where
B. which
C. that
D. when
上升段发生泄漏有那些参数变化温度、（）、给水量、蒸发量、（）。
