英文.翻译.

按照外国人的语言习惯
应该是
You could look at it,but you couldn't touch (it).
用COULD语气较为委婉.

You can look at it, but you can't touch it!

Look only, Never touch!

上面三中都可以

口语化一点就是我这种

don't touch it ,but you can have a look

You can see and can't touch