1. Expression：in one’s shell

Explanation：In a quiet or withdrawn state. （处于安静或孤僻的状态）

1. 比喻某个计划，策略等还在酝酿中，尚未确定。2. 指有些人生性害羞，性格内向，不喜欢和人交谈。

Usage：也可以说为：into one’s shell，常和动词go 搭配，即：go into one’s shell.

Example：After getting mugged, I went into my shell and didn't speak to anyone for nearly a week.

在遭到抢劫之后，我害怕而变得孤僻，将近一周没有和任何人说话。

I'm not good around large groups of people; I usually just go into my shell and wait until I can be alone.

我不擅长于和一大群人打交道——我通常不和人说话，一直等到我可以一个人呆着的时候。

Her rejection of him seem to have make him go into his shell.

他遭她拒绝后就更不爱吭声了。

A: My daughter is always in her shell when a stranger is around. I am a bit worried.

我女儿一遇到陌生人就感到拘束，我都有点儿担心了。

B: Take it easy. Just encourage her to make more friends.

别担心，鼓励他多交些朋友。

2. Expression：out of one’s shell

Explanation：Less shy, reserved, or reticent and in a more sociable, outgoing, or enthusiastic state. （不再拘谨，不再沉默）

Example：Samantha was quite a quiet girl growing up, but she really started coming out of her shell in college.

Samantha在成长过程中是一个非常安静的女孩，但是她真的在大学读书的时候就开始变得善于社交。

Jack is actually a very funny, engaging guy once he's out of his shell.

一旦杰克不再害羞，他实际上是一个非常有趣、迷人的家伙。

She used to be so quiet, but now she's really coming out of her shell and chatting to everyone.

她一向沉默寡言, 但现在可真活了, 跟谁都能谈得来。

Music drew the shy girl out of her shell.

音乐吸引那个害羞的姑娘走出了深闺。