1.This fund is collected by the kids to help orphanage children in the city.

-The kids raise this money to support orphans in the city. (More concise and natural)

-This money is being raised by children to benefit orphans living in the city. (Slightly more formal)

2. They said that the Temple of Literature was built in 1070 during the Ly Dynasty.

-It is said that the Temple of Literature was constructed in 1070 during the Ly Dynasty. (Impersonal "it" structure)

3. Covid-19 has seriously affected all countries in the world.

-The Covid-19 pandemic has had a severe impact on nations globally. (More formal vocabulary)

-Every country worldwide has been significantly impacted by Covid-19. (Emphasis on the universality of the impact)

4.If a satellite cannot be fixed, it will be left floating in space forever.

-A satellite beyond repair will remain in orbit indefinitely. (More concise and technical)

-Should a satellite prove irreparable, it will be abandoned to float in space. (More formal and emphatic)

5.English is spoken by people all over the world as a second language.

-English is used as a second language globally. (Simpler phrasing)

-Worldwide, English is a commonly spoken second language. (Emphasis on common usage)

6.Why do you suggest booking a room in advance?

-What are the advantages of booking a room beforehand? (Focuses on the benefits)

-Could you explain why it's recommended to book a room ahead of time? (More polite and indirect)

7.Last year, I had fewer friends than I do this year.

-My circle of friends has grown since last year. (Positive framing)

-I've made more friends this year compared to last. (Focuses on the act of making friends)

8.My sister doesn’t like red meat, and neither does my mother.

-Neither my sister nor my mother enjoys red meat. (More formal and concise)

-Both my sister and my mother dislike red meat. (Slightly stronger emphasis on dislike)

9.We have been teaching the street children for three months.

-We started teaching street children three months ago and continue to do so. (More explicit about the ongoing nature of the action)

-For the past three months, we have been providing education to street children. (More formal and emphasizes the provision of education)

10.I think English is easier than French.

-In my opinion, English is less difficult than French. (More formal)

-I find English to be simpler than French. (More subjective phrasing)