Here are the most suitable options for filling in the blanks with "will" or "be going to":

1. I need to fix the broken chair. **Will** you help me?
2. It's been decided that we **are going to** the beach tomorrow.
3. I think **I am going to** (or **I will**) visit the sea some time in the near future.
4. I **will** translate this poem so that you can understand it.
5. Don't worry. I **will** help you.
6. Look at that boy. He **is going to** jump.
7. **Are you going to** travel anywhere next summer?
8. As planned, he **is going to** ride from Can Tho City to Ca Mau.
9. I **will not** hang out with you since I have a test tomorrow.
10. I feel tired. I **am going to** have some rest.
11. “It’s very hot here” – “I **will** turn on the air-conditioning.”

Feel free to ask if you need further assistance!