when的用法四种句型
when的用法四种句型：be doing sth…when；be about to do sth…when；hardly…when；had just done…when。 1、be doing sth…when 例：He was still smiling when the door opened and his wife came in. 他正笑着的时候门突然开了，他妻子走了进来。 2、be about to do sth…when… 例：We were about to start...