Some sentences 1.How long did he spend on read this book？ 2.You spend too much time on computer games,I think it is not good for you 3.These mathematical problem are too difficult,no one can finish the homework 4.When we cross the bridge,we saw a boy fall into the river 5.This theatre is too big,no one can easily find the exit 6.Don't be afraid of make a mistake when you speak English 7.It is not everyone like to eat dumplings 8.As students we have to take full advantage of our free time 9.Whatever you what to doing,you have to tell me at first 10.Because of the weather is rainning,so they stop to play football