during 能用成 during 1999 to 2001吗?

during during the trip和on the trip?during可以吗 I am going to Guilin during () () () holiday. I went to Beijing during summer v______. I tried to telephone him during off I want to have a trip during during the during break 英语翻译during. during sleeping还是during sleep during和while的区别?would you know what to do [during] a really I want to see my aunt during my stay in Shanghai.during后为什么是