The web is fantastic at many things, e-mail, e-commerce, for example. But _____ your name is Amazon Or Google, making money has proved hard.
A.ifB.althoughC.unlessD.as在线课程C
解析：
四个选项分别表示如果、尽管、除非和由于。根据题意，网络赚钱已经被证明是很难的，除非你的名字是亚马逊或者谷歌。故选C。