----What do you know the of are the pig influenza in humans?-- usually similar to regu

问题补充：

----What do you know the of are the pig influenza in humans?

---- usually similar to regular human seasonal influenza .

A. symptoms

B. sympathy

C. symbol

D. symptom

答案：

(答案→)A. symptoms

B. sympathy

C. symbol

D. symptom

解析：A考查名词词义辨析。句意：你知道人类感染猪流感后的症状吗？通常与患流行性感冒症状相似symptom症状符合句意;sympathy同情；symbol符号。从what are可以看出是复数名词。