首先，我们负担不起搬家。

___To ___begin ___with, we can't afford to move.

首先，它不污染环境，而且我认为是时候我们开始考虑环境了。

___To ___begin ___with, it doesn't pollute and I think it's time we started thinking about the environment.

首先，这个项目需要太多时间。

___To ___begin ___with, the project requires too much time.