I don't even know the reason, but I suppose I wouldill be active there after not longin a little while. I don't even know the reason, but I suppose I will be active there in a little while.

20 to 30 degrees Celsius would be the nicerst weather for humans to live in, however there is no thissuch place. 20 to 30 degrees Celsius would be the nicest weather for humans to live in, however there is no such place.

China has an old saying,"赠人玫瑰, 手有余香" i. It means that when you give roses to other people, your hands remtain the rose's aroma. China has an old saying,"赠人玫瑰, 手有余香". It means that when you give roses to other people, your hands retain the rose's aroma.

That's such a cool idiom :)

Now I don't like snow because it causes many troubles in our lives.; Now I don't like snow because it causes many troubles in our lives;

Ffor example, traffic issues, agricultural issues and so on. for example, traffic issues, agricultural issues and so on.

I've joined this sentence onto the last sentence. If you are still talking about the previous idea, it's best not to begin sentences with "for example". :)

I like island countries because they have such beautiful scenery. I like island countries because they have such beautiful scenery.

The word "such" makes this sentence feel more natural. Alternatively, you could say "I like island countries because of the beautiful scenery".

Vast seas, tall mountains, green trees and colorful flowers. Vast seas, tall mountains, green trees and colorful flowers.

Again it somehow feels more natural to write "sea" as plural here :)

I checkedlooked through/at some photos of KL. I looked through/at some photos of KL.

The twin towers are very beautiful, but I don't know their names, andor what they are for. The twin towers are very beautiful, but I don't know their names, or what they are for.