1.吃得太多有害于我们的健康
-> Eating too much is not good for our health.
或: Eating too much is bad for our health.
2.我将尽力把这份工作干好
-> I will try my best to do this work.
3.他也许是一位老师
-> He may be a teacher./ Maybe he is a teacher.
4.我有许多作业要做
-> I have a lot of homework to do.
5.虽然他已80岁了,但他还相当健康
-> Although hs is 80 years old, he is pretty healthy.