you must watch it with your eyes.“with”为什么不用“by”?

you must watch it with your eyes.“with”为什么不用“by”? do you take your eyes with you? What can you do with your eyes? You do this with your eyes.是什么 With your eyes 歌词 it is only when you see that with your own eyes that you can Something must be wrong with your watch,___?反义疑问句 You must always be careful with it . You must check in with your ID card if you wany to keep it f ----a dog lived with your family ,it would watch you cooking What can you see with your eyes hurt? 脑筋急转弯what can you see with your eyes shut