对外贸易:指国与国之间商品与劳务的进出口交换活动。在一个国家的对外经济关系中居于主导地位,是其他对外开放形式的基础。 ( )
参考答案:对
在CPM1A中,若TIM的设定值为200,则延时时间为
A.1s
B.10s
C.2s
D.20s
— You must be looking forward to your trip back to Sydney.
— Yes. I ______ wait any longer.[ ]
A. can't
B. mustn't
C. needn't
D. shouldn't