The only limits you have are the ones you set for yourself.

我们必须投资于不仅能提高效率而且能减少环境影响的技术。

I know I'm not an ordinary year-old. I've had surgeries so that I can breathe, see, and hear without hearing aids, but it all makes me look unusual.

地球及其周围的水域实际上必须具有其阴影所揭示的形状，因为它以完美的圆弧遮蔽了月亮。