由天然气中分离出的（）以上烃类可以做燃料，也可做化工原料，可用于生产各种烯烃。
A.C1
B.C2
C.C3
D.C4
参考答案：B
组织学习的内容包括三个方面的改变，分别是（）。
The settlement is home to nearly 1,000 people, many of _____ left their village homes for a better
life in the city. [ ]
A. whom
B. which
C. them
D. those
