我国()的土壤侵蚀容许量为500t/(km·a)。
A.东北黑土区
B.南方红壤丘陵区
C.西南土石山区
D.西北黄土高原区
E.西北土石山区
参考答案:B, C
进口须办理检疫审批的动植物及其产品,必须凭进口合同办理检疫审批手续。 ( )
______ teacher and _____ student has been invited. Which is wrong? [ ]
A. Many a, (many a)
B. Every, every
C. No, no
D. Each a, (each)