Question

Tom is twelve years old,Mike is thireen years old.合并为一句

Answer 1

加个and 就可以了。
如：Tom is twelve years old and Mike is thireen years old。

Answer 2

Tom is twelve years old and Mike is thireen years old.
或者：
Tom is twelve years old but(while) Mike is thireen years old.
应该都可以吧，语气不同~~

Answer 3

Mike is one years older than Tom.

Answer 4

中间加个and就可以了。。