There is a rush 意思they are so easy to get the books .there is a rush.

There is a rush 意思they are so easy to get the books .there is a rush.
There is a rush 意思
they are so easy to get the books .there is a rush.

There is a rush 意思they are so easy to get the books .there is a rush.
他们很容易获得书本.有一股（获得书本）的潮流.
rush本意是急着要什么东西,这里可以理解成trend,也就是热潮、潮流的意思.
给你个例子帮助理解一下：美国人喜欢说某个刺激的东西给了他们一股“adrenaline rush”,就是一股肾上腺素的潮流,这里面的rush就变成了名词,也就是“流、潮流”的意思了.
你给的句子基本是引申出去了.

有一股湍流

当时是一股热潮