when 句型：

　　(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 when it began to rain.

　　我们刚要出发，天就开始下雨了。

　　(3) had not done sth --- when ---/ hardly --- when ---

　　例： He had not fallen asleep when the telephone rang.

　　他刚要入睡电话就响了。

　　(4) had just done ---- when ---

　　例：I had just gone to bed after a very hard day when the phone rang.

　　在劳累了一天之后我刚刚就寝，电话铃就响了。

相关链接：

高一辅导 
高二辅导 
高中数学辅导 
高中辅导