第一， 情景对话

A: What do you do first in the morning?

你早晨起来第一件事做什么？

B: I play the violin to keep my hand in.

拉小提琴，练练手。

A: Yes? Is it necessary for an expert like you?

是吗？像你这样的专家有必要吗？

第二， 词海拾贝

keep one’s hand in

exp. To continue to do something in order to maintain a particular skill or ability. （继续做某事以保持一种特殊的技能或能力，保持练习）

e.g. I've mostly stopped acting, but I will do a play occasionally, just to keep my hand in.

我基本上已经不再演戏了，但我偶尔也会演一出戏，只是为了保持演技。

e.g. I should very much like to do some occasional teaching to keep my hand in.

我很想偶然教教书，以免荒疏了教学业务。

e.g. I like to play tennis regularly, just to keep my hand in.

我喜欢经常打打网球, 以免技术生疏。

e.g. She practices her English every day to keep her hand in.

她每天练习英语，以不使其生疏。

第三， 语汇积累

Play the violin：拉小提琴

第四， 口语句型

It is necessary for someone to do something. （某人有必要做某事。某人必须做某事。）

e.g. It is necessary for us to exercise the duties of our office.

我们必须履行公务责任。

e.g. It is necessary for us to take part in physical labour.

我们参加体力劳动是十分必要的。