这道题一直想不通~!很纠结.急等解答 谢谢大家了~! _____there are a large number of chemical factories, the air is likely to be polluted A that B where C once D as 答案是B 为什么不选C“一旦…”或者D“因为…”
这是where therebe句型,指的是“有···就一定有···”, 像“where there is a will ,there is a way.有志者事竟成。 Where there is a smoke, there is a fire.无风不起浪。” as和once这种用法是少之又少~~指因果关系时候,where there be句型是固定的。