1、come down

(成本、水平或数量)下降，降低

Interest rates should come down.

利率应该降低。

If you buy three bottles, the bottle price comes down to 2.42.

如果买3瓶，价格会便宜一些，每瓶2.42英镑。

落下;降落

The cold rain came down.

下起了冰冷的雨。

The curtain came down after the first act.

第一幕过后，幕布落了下来。

2、come across

偶然发现;偶然遇见

I came across a group of children playing.

我碰到一群正在玩耍的小孩。

We like to identify and celebrate women's success whenever we come across it.

每当女性取得成功，我们都会表示认同并予以颂扬。

使产生…印象;给人以…的印象

When sober he can come across as an extremely pleasant and charming young man.

没喝醉的时候，他看上去似乎是个极为彬彬有礼、讨人喜欢的小伙子。

He came across very, very well.

他给人的印象非常非常好。