Whenpeopletalkabouta的精選

問題詳情：閱讀短文，從A、B、C、D四個選項中選出可以填入空白處的正確*。Whenpeopletalkaboutairpollution,theyareusuallythinkingaboutoutdoorair  1 .Butdoyouknowthatthereisalsoairpollutioninsidehomes,offices...