Sure! Here are the answers to the questions based on the provided passage.

5. **Can we live on a planet in our system?**
- No, it is not possible to live on any of the planets in our system due to their harsh conditions.

6. **Why is it possible to land a spaceship on Mercury?**
- Spaceships can land on Mercury because it has a solid surface, despite having extreme temperatures.

7. **How is the atmosphere in Mars?**
- Mars has a thin atmosphere, which does not support human life.

8. **Does Venus have a thin atmosphere?**
- No, Venus does not have a thin atmosphere; it has a very heavy atmosphere.

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Now for the sentences:

C. **Use the given words or phrases to make a complete sentence.**

1. **He/read/book/his room/when/he/hear/big explosion.**
- He was reading books in his room when he heard a big explosion.

2. **Robots/future/work/efficiently/than/now.**
- Robots in the future will work more efficiently than now.