A man is known by the company he keeps.

视朋友，知其人。

Birds of a feather flock together.

物以类聚，人以群分。

Friends and wine improve with age.

朋友和酒都是越久越醇。

A friend to all is a friend to none.

和谁都好的朋友不一定是真的好朋友。

Lend your money and lose your friend.

你借钱给朋友就会失去这个朋友。

indeed

真正的，的确

out of touch

对某些情况不了解

I'm not really in touch with what young people are interested in.

我真的不了解现在的年轻人对什么感兴趣。

I didn't watch TV laterly, so I'm completely out of touch.

我最近没怎么看电视，所以可说是对当下的时事一无所知。

I'm so out of touch with current music.

我不知道现在流行怎么样的音乐。

keep in touch (with)

是指通过电话等方式维持联系(touch)

loss touch with

失去联系就是

be out of touch with

联系不上就是

I loss touch with him.

我和他失去了联系。