1. They won the semifinal between their school and Chicago Middle School. And then they won the finals in the baseball match between London Middle School and New York Middle School.

2. The title of the TV program is "Water Pollution." The strong point of the program is that we can learn a lot of new fact about the environment and the pollution in the city. The weak point of the program is as follows. It is biased because they do not know the water pollution in detail.

3. What's on TV at 19:30?
It's "Sitcom: Three Friends."
(Is this correct expression above? How do we read 19:30? Nineteen thirty? Or Nineteen thirty o'clock, Or nineteen thirty p.m.?)

4. Is 'drama' a soap opera? (question)
what is the difference between 'drama' and 'soap opera.'?

1. They won the semifinal between their school and Chicago Middle School. And then they won the finals in the baseball match between London Middle School and New York Middle School.

Delete the word "And" at the beginning of the second sentence; everything else looks good.

2. The title of the TV program is "Water Pollution." The strong point of the program is that we can learn a lot of new fact about the environment and the pollution in the city. The weak point of the program is as follows. It is biased because they do not know the water pollution in detail.
Television show titles need to be in italics, not in quotation marks. Use the plural form of "fact." After "as follows" you should use a colon (:). In the last sentence, it's not clear who "they" are; in addition, I'd change the word "the" to "about."

3. What's on TV at 19:30?
It's "Sitcom: Three Friends."
(Is this correct expression above? How do we read 19:30? Nineteen thirty? Or Nineteen thirty o'clock, Or nineteen thirty p.m.?)
Television show titles need to be in italics, not in quotation marks. Also, when using a 24-hour time reference, you'd just write 19:30 -- no "o'clock" or "p.m." -- or you could say 7:30 pm.

4. Is 'drama' a soap opera? (question)
what is the difference between 'drama' and 'soap opera.'?
Both questions look fine with a couple of little corrections. Put a capital W at the beginning of the second sentence, and delete the period at the end of the second sentence. The question mark is all you need there.