口岸通关效率是决定北部湾港竞争力的重要因素。
参考答案:错
—He should have come to join in the thorough cleaning.
—He ________, I think. It's not his turn.
A.needn't have to
B.needn't have
C.didn't have to
D.doesn't need to
我国资源的基本国情是[ ]
A.取之不竭,用之不尽
B.总量丰富,但人均不足
C.总量很少,大部分依赖进口
D.人均资源丰富,但种类很少