At that time,we should be careful.这句话有错误吗?

We should be more careful _____much time on computer games. Be careful of this dog which doesn't bark.这句话有错误吗? At that time life is very hard fou her这句话有没有错误? all of us should be very careful 为什么这句话中有be? You should be more careful next time. We should be confident that we can learn it well.这句话that后面的句 We should be more careful ______ much time on computer games they should be careful to the dangerous这句话是对的吗 这It is high time that we should do有这种用法吗 这个句子we should be careful how much we eat of it.有疑问! We should be careful when we ___a busy street say that again,I promise you'll be regret.这句话有错误吗