几个中文句子翻译成英文,各位英语达人帮帮忙吧,谢谢!

Don't let yourself lost in unrealistic hopes in some developed countries there are still a lot of social problems if we cannot survive three weeks ago I ordered some books but haven't received in some cases we have to learn how to solve their own problems without air and water people
下面的几位,可以不用机翻吗?
我是英语老师,
再问： 我们都知道如果没有空气和水人们就不能生存 这句话具体点怎么翻译
再答： We all know people can't live without air and water.