For one thing, e-books barely existed a decade ago, but have exploded in popularity since Amazon introduced its Kindle a few short years back, and a host of rivals rushed in with copycat versions.
比方说,电子书在十年前仍是个稀奇物,但自从多少年前亚马逊推出它的电子书阅读器Kindle之后,电子书很快在人群中盛行了起来,良多亚马逊的对手紧接着就推出了模拟版。