用括号内所给动词的适当形式填空。
小题1:In the past three years, my home town ______________(change) a lot. already.
小题2:It’s hard to say what ____________ (happen) in 100 years in our country.
小题3:They_______________(not travel)to Shanghai next week, are they?
小题4:The students________(chat) from 6 to7 yesterday evening.
小题5:When I got to the station yesterday morning, my friends _______(wait ) for me at the entrance.
小题6:If it__________ (not rain) tomorrow, we’ll go hiking.
小题7:He____________ (not write) a letter to his mother yet. He has to do that soon. His mother misses him very much.
小题8:Would you please__________(not make) such a big noise. The baby is sleeping.
小题9:It’s a long time since we ________(meet) last time, isn’t it?
小题10:----How many times _______the girl __________(forget) to take the keys to her home?
----At least three times.
小题11:You must spend as much time as you can ________ (practise) playing the piano.
小题12:They_______(live) in Wuxi since they were born.
，正电荷
，正电荷
，负电荷
，负电荷