The air inside a house or office building often has higher concentrations of contaminants .heavily polluted outside air.A.than does B.more C.as some that are D.like of A为什么选A?
The air inside a house or office building often has higher concentrations of contaminants .heavily polluted outside air.
A.than does
B.more
C.as some that are
D.like of A
为什么选A?
意思是：房屋或办公大楼内的空气 总是比室外已经严重污染的空气 有着跟高的空气污染物含量。
more/-er...than...的比较句式想必你应该知道的，does放在这里是倒装，因为前面的主语“室内空气”的动词是"has"，所以than后面的主语“室外空气”动词倒装用的是does咯^^
你原句的完整句子是：The air inside a house or office building often has higher concentrations of contaminants than heavily polluted outside air has high concentrations of contaminants .
然后has high concentrations of contaminants 与前面相同，于是用does这个代动词来代替。does这个词一般放在最后，放在前面也行。如：He runs faster than I ran.一般我们讲成：He runs faster than I do.
意思是：房屋或办公大楼内的空气 总是比室外已经严重污染的空气 有着跟高的空气污染物含量.
more/-er...than...的比较句式想必你应该知道的,does放在这里是倒装,因为前面的主语“室内空气”的动词是"has",所以than后面的主语“室外空气”动词倒装用的是does咯^^