Hi Haiyang,

This is really good! You use a good variety of vocabulary here and it sounds very naural. I only saw a few places that you could improve:

Man and Technology

Science and technology is developing rapidly in modern times, changing and transforming the whole world in a radical way.

It has, on the one hand, made our lives much easier, providing us with all kinds of conveniences, but on the other, also caused us trouble.

Many work Many tasks / A lot of work ("Many" can only be used with count nouns. "Work" is a noncount noun. However, in positive sentences, we usually avoid using "much" and choose "a lot of" instead. However, it can sometimes sound slightly informal so another option would be to switch "work" for a countable noun alternative, such as "tasks")that had to be done by ourselves is now been carried out (great use of that phrasal verb!) by computers. As we become more and more relied rely (verb) more and more / become more and more reliant (adjective) on technology, our abiliy to think and act independently is undermined.

Letters are supplanted by emails. Conversations are replaced by text messages. Writing with a pen becomes a form of art, and even books are beingen read on a screen.

As said by Sydney J. Harris, "The real danger is not that computers will begin to think like men, but that men will begin to think like computers." 

Concerns about the decline of men's mental capacities are not unfounded. Despite all the tasks technology can help us to accomplish, it is still necessary for us to sharpen our thinking skills and make full use of our own brains.