最好能给我讲一下语法.Children are warned to be careful when ______ the stre_英语解答

最好能给我讲一下语法.
Children are warned to be careful when ______ the street.A crossing B.crossed C.being crossed

人气：448 ℃　时间：2020-01-29 17:01:29

解答

crossing
省略成分 Children are warned to be careful when （they are crossing）the street