If time travel is possible, where are the tourists from the future?

改变始于一小步，但需要集体的努力才能使其持久。

If you're trying to achieve, there will be roadblocks. I've had them; everybody has had them. But obstacles don't have to stop you. If you run into a wall, don't turn around and give up. Figure out how to climb it, go through it, or work around it.

一个人有身份有地位的时候朋友很多，但危难时候却没人与之交待。

The value of a mental process is in its survival utility.