朱鹤亭子女:这个是个病句吗？英语的

To throw the rubbish in to wastebins is good for us to protect our environment.
我想应该是这样的。
然后用形式主语是
It is good for us to throw the rubbish in to wastebins to protect our environment.

是
正确如下:

It's good to protect our environment is to throw the rubbish in to wastebins.

楼上的你也错了！！
be good for 是固定搭配——对...有益
不过如果要改动的话，我同意改成楼上的第二种形式！
Throwing the rubbish into wastebins is good for
protection of our environment.

It is good for us to throw the rubbish in to wastebins so that (to)不确定要不要加TO protect our environment.

楼上的好像有点问题
It's good to protect our environment to throw the rubbish into wastebins

或者Throwing the rubbish in to wastebins is good to protect our environment

To throw the rubbish into wastebins is good for protecting our environment.（这个一定对）

或者这种改法：It's good to throw the rubbish into wastebins for protecting our environment.（不是很确定的）