选址之初会通过对人口密度、客流量、人口流动性的测算来预计（）的程度。
A、销售能力
B、产品市场
C、购买力
D、人口密度
参考答案：D
Leaving for work in plenty of time to catch the train will () worry about being late.
A. rule off
B. prevent
C. avoid
D. obviate
What's the（）difference between the two parties?
A.essential
B.necessary
C.dominant
D.great
