One of the screws on his project keeps coming loose.

他那装置上螺钉总是拧不紧。

And that's called " slack, " when the rope isn't tight.

当绳子不紧时，这就是所谓“松弛”。

15. It's neither too tight nor too loose. It fits perfectly!

不紧也不松。正合适！【拓展】1. 痱子：heat rash2. Trash and garbage ： 美式英语垃 (可替换使用)3. 透气尿不湿：breathable diaper4. 舒适裤腰：comfortable waistband5. 这尿不湿吸水性极强。This diaper can hold a lot of pee。6. Pull-ups 是复数，拉拉裤有 2 条腿所以要加 s，词要用 They 和 them，或者可以说 pull-up diaper，单数就好啦。7. Rip=tear. 表示撕开，可以互换使用。但是 rip 语气更加强烈。

" Did you lose your cellphone? " " Loose" is an adjective which means not tight, and " lose" is the opposite of " find" .

“你手机丢了吗？”“松”是形容词，意思是不紧，“丢”是“找到”反义词。