帮我看一下这段英语对话的语法有什么要修改的吗?

帮我看一下这段英语对话的语法有什么要修改的吗?
A:do you think they will find life on Mars?
B:i don´t know ,but someone tell me :they´ll fin life on Mars .what do you think about this
A:i´m not sure if that´s true.because they don´t have any evidence .
B:i think so too ,but i remain hopeful life exists elsewhere.
A:do you really think so?i think dosen´t exist anywhere but on Earth.
B:i don´t believe it ,i think they´ll find some evidence
可以把它改的稍微复杂点吗？可以加一些论证或者自己的话

A:Do you think they will find life on Mars?（这句没问题）
B:I don´t know ,but someone told(不是tell或tells,因为别人已经告诉了你,已经是过去式了) me that （当在陈述别人说的话是,用that,不用冒号）they´ll find life on Mars.What do you think about this 举个例子：如果你要对A说B会完成作业的,在英文里面就会对A说 “B told me that he will complete his work.”而不是“B told me ：he will complete his work.”
A:I´m not sure if that´s true.because they don´t have any evidence .（这句没问题,if和whether都一样,随便你选）
B:I think so too,（其实可以用Likewise,表示跟A想法一致） but I still believe life exists elsewhere.（个人认为remain hopeful（保持乐观）不恰当,still believe（依然相信）才对）
A:Do you really think so?I think life doesn't (这里注意does not的缩写是doesn't不是dosen't)exist anywhere except (but的意思是不过,except的意思是除了.不可能说“不过在地球上”,应该说“除了在地球上“）on Earth.
B:Of course ,I believe they´ll find some evidence in the near future.
LZ发的最后一句是大问题.第1,A问B你真的相信宇宙除了地球以外还有生命,B当然要说自己相信啊,怎么能说B不相信呢?B再说第2句话不是说了自己虽然没有亲眼看到任何证据,但相信除了地球以外还有生命吗?不然就自相矛盾了.
第2,即使B改变了想法,说自己不相信了,就应该说“I don´t believe it ,I think they´ll not find any evidence"（我不相信,我不认为人们会找到任何证明宇宙有其他生命的证据）而不是”I don´t believe it ,I think they´ll find some evidence（我不相信,我认为人们会找到一些证明宇宙有其他生命的证据）再次自相矛盾.
最后改的稍微复杂点：
A:Do you think they will find life on Mars,or any planet in the space?
B:i don´t know ,but scientists have been studying about possible life in space long time ago.An specific example will be them sending many satellites to Mars,collecting rock samples and finding out the atmosphere condition.What do you think about this
A:Even though they have been searching life in space for quite some time.They still did not find any evidence of life in space so far.
B:I agreed with you ,but I still believe there will be life in space except Earth.
A:Do you really think so?I think life doesn't exist anywhere except Earth because no other planets contain water,right amount of oxygen and a atmosphere in good condition to support for lifes.
B:The space is so huge and the space known by human is so limited,there are still many galaxies which human has no yet discover and there might be lifes there.I think with the improvement of technology everyday,our scientists´ll surely find life in other part of university sooner or later!