To put it simply, charging tourists from home and abroad differently is far from fair.

简单地说，对国内外游客收取不同的费用是不公平的。

To put it simply, it's complicated.

简单地说就是，这很复杂。

To put it simply, the earth is a small planet.

简而言之，地球是个小行星。

One man put it simply: "It's a Japanese thing."

一个人经此描述的很简单，“这是日本的事情。

To put it simply, that's because of air pollution.

简言之，那是因为空气污染的缘故。