with 和then中间加什么

1.He exchanged a quick smile with her then entered the lift.他和她匆匆相视一笑，然后走进了电梯。

2.'Well, get on with it then,' said Dobson, whereupon Davies started to explain.“那好吧，继续吧，”多布森说，于是戴维斯开始解释。

3.The envelope has been tampered with and then taped shut again.信封被人动过手脚，然后又用胶带封上了。