改正下列句子中的错误。
1．People throwed cans, paper, bags and so on into the river.
throwed→threw
2．During my summer vacation, I spent half a month in the country where I played very happy. happy→happily
3．We must pay attention our pronunciation when we speak English.
attention后加to
4．It's high time we do something to reduce the number of traffic accidents. do→did
5．There have been more and more road accidents happened in recent years. happened→happening
6．Dr.Smith, together with his wife, are to arrive by taking an evening flight.
are→is
7．Would you please meet my uncle at the airport because this is his first time visit to the US? 去掉time
8．I have many collections of stamps, some of them are my favorites.
some前加and或them→which
