vary with 和vary by都是随.变化,那有什么区别呢?

vary 就只是个动词,意思你也已了解,差异只在于后句表达什么、用什么介词合适,如此而已.
例如：
These will vary with time.这些会随时间而改变.
Although they are all grapes,the taste vary by the region in which they're grown.
尽管它们都是葡萄,口感（味道）会因为产地不同而有所变化（不同）.