导致产业活动地域联系的主要原因是

    ①资源的地区差异  ②区域经济发展的不平衡  ③人口密度的区域差异  ④政治体制的地区差异 [ ]

A、①②

B、③④

C、①③

D、②④

--- Compared with that film, this one is ______ but not _______.

---I see, and I will see that one this evening.

A．longer, as good

B．long, good

C．longest, best

D．long, so good