围棋级别划分:for example为什么简化为e.g

for example为什么简化为e.g for example for example can you give an example for the consumer-to-consumer(c2c) kind of e-commerce can you give an example for the consumer-to-consumer(c2c) kind of e-commerce “就以…为例”可不可以用take sth. for example? 请问：for example for instance的区别 such as 和for example 的区别 such as 与for example的区别 for example for instance such as 的区别？