Where's my pen? [ ]
A. It's in the desk.
B. It's under the desk.
C. It's on the desk.
答案:B
亚洲和北美洲的分界线是 ( )
A.苏伊士运河
B.土耳其海峡
C.巴拿马运河
D.白令海峡
选煤厂快速检查的项目有哪些?