1.带几件暖和的衣服,以防天冷（in case）
Take some warm clothes in case the weather is cold.
2.小孩子学外语很快（pick up）
The kids pick up foreign language quickly
3.如果你不快点,就赶不上火车了
You'll miss the train if you don't hurry up
4.吸烟有害健康
smoking is harmful to our health
Smoking is bad for our health
5.他们老是犯同样的错误（keep on
They always keep on making the same mistakes.