按不同形式要求用英语造句.

1.以 to do 开头 To clean the classroom is our task this afternoon.
2.以 介词+doing 开头On hearing the good news ,we all jumped with joy.
3.以 doing 开头Walking in the street,I met an old friend of mine.
4.以 done 开头Seen from the top of the mountain ,the city looks very small.
5.以 having done 开头Having finished the work ,they went home.
6.以 when/while doing 开头when /while watching TV,we heard a cry.
7.以 when/while done 开头when seen from the top of the mountain,the city looks very small
8.以 if/until/although/once/unless done 开头各造一句
If untreated,the disease will become serious.
keep silent untill told to speak.
Although invited,I don't want to go to his party.
Once gained ,our friendship will get firm.
I will pick you up at the theatre unless told you won't come.
9.以 adj.或形容词性短语开头
10.以 连接词+adj.开头