我们每个人的大脑就像一台机器，如果你总是不用它，它就会生锈。

The mind is like a parachute, it won't work unless it's open (It doesn't work unless it's open.). 1.脑筋就像一个降落傘，只有打开，它才能运转。 脑袋就像一把降落伞，只有打开它，它才能运转。 2.脑筋就像一个降落傘，除非你打开它，它不能运转。 脑袋就像一把降落伞，除非你打开它，否则它不会运转。 3.脑筋就像一个降落傘，除非它是打开的，它不能运转。 脑袋就像一把降落伞，除非它被打开，否则它不会运转。 I prefer to say - 思维(or 脑袋)正如降落伞，只有打开它(or 经常用)，它才能运转。 I hope it helps. :)

第二种翻译可取！ 但是， it is better to traslate "mind" into "思想"或“思维”， 这样才是更贴切的中文表达。 我的翻译是 “人的思想就像降落伞：不开则无用” this "open" in english should be traslated a little differently in chinese, because one word "open" in english can be explained in many ways as verb, so you should also ues different chinese charactor respectively to express precisely what you really want to say. as you can say "open your mind " and also "open the parachut" but, it is not very precise to say “打开思想” even though we usually say "打开降落伞"，"开放思想" will be better. and a more better and usual way is to say "解放思想"=”open your mind“ in china. 问题补充: Oh one other I thought of is 脑筋就像一个降落傘，除非它是打开的，它不能运转。 你漏了一个“否则”， 如果用“除非。。。”，后面一般接“否则。。。” “除非它是打开的，否则它不能运转”

脑海一朵降落傘，不開不可用.

脑筋就像一个降落伞，只有动它才管用。