1, the problem is solved, and I feel that there is nothing simpler than this. However, in seeking answers, it is like catching clouds in the sky.

Try to focus on one focus, just like the lens.

The best assistant in science is your own mind, not anything else.

Learning this matter doesn't care whether anyone teaches you. The most important thing is whether you have consciousness and perseverance.

5. Never give up on yourself ... Go, as long as you go, you will naturally have strength.