1.out,and,have,let's blow,cakes,some,candles,the.(连词成句）
答案：let's blow the candles out and have some cakes .
2.away,quickly,must,from,danger,the,we,stay.(连词成句）
答案：We must stay away from the danger quickly.
3.got,I,new,caloulator,have,a,my,farm,mother.(连词成句）
答案：I have got a new calculator from my mother .
4.study,for,cleaned,the,father,his,Ben.(连词成句）
答案：Ben cleaned the study for his father .
5.over,with,there,he's,in the corner,ball,the .(连词成句）
答案：He's with the ball in the corner over there .
6.Let's go and see.(改为同义句）
Let's go and have a look.
7.What time is it?-----It's ten fifteen.
What's the time?------It's fifteen past ten.
8.I would like a computer as my present.(改为同义句）
I want to have a computer as my birthday present.问题补充：
1.Please put these knifes in the bag,( 找出错误的地方,并改正）
a b c d
c-----knives(名词复数问题:通常fe结尾的名词,改复数的时候,变成v +es）