单选题 6.There is a real possibility that these animals could be frightened, ______a sudden loud noise.

【正确答案】 C

【答案解析】should there be a sudden loud noise“如果突然出现巨大的响声”，这是省略if的虚拟条件句将来时，把助动词或情态动词提前，相当于if there should be a sudden loud noise。