我国出产冬小麦的农业基地是[ ]
A、松嫩平原
B、三江平原
C、华北平原
D、珠江三角洲
答案：C
什么是知识普及服务？
Where are _____ pens? Are _____ in the drawer?[ ]
A. my; they
B. /; they
C. your; you
D. his; them
