Chinese vessels 646 000 square kilometers in the southern Indian Ocean in search of the m

问题补充：

Chinese vessels 646,000 square kilometers in the southern Indian Ocean in search of the missing Malaysian flight MH370.

A. have covered

B. have looked

C. has travelled

D. had searched

答案：

(答案→)A. have covered

B. have looked

C. has travelled

D. had searched

解析：考查动词辨析。句意：中国的海事船已经覆盖了南印度洋646000平方千米的海域，来搜寻马来西亚失联客机MH370。cover有“覆盖，走过（一段路程）”的意思，search后跟地点或要搜寻的人或物，这里与kilometers不搭配，故选A。