It is reported that large amounts of locusts(蝗虫) in their activity in the north now.A. is

问题补充：

It is reported that large amounts of locusts(蝗虫) in their activity in the north now.

A. is

B. are

C. was

D. were

答案：

A. is

(答案→)B. are

C. was

D. were

解析：考察主谓一致。large amounts of locusts大量蝗虫是复数，故谓语动词用复数形式，结合时间状语now可知是表述的现在的状态，故用一般现在时态，选B。