3.
1. Mr Wu is a very creative man. He lives for his inventions. I like him, because he is working on his inventions to make people's life more easy.
2. Ms Dong is very supportive, she helps earning money for the family, and she doesn't tease him for his hobby. She hopes that someday he will earn money for his robots.
3. I agree, because if you're creative and inventive enough, you could make a robot out of anything.
5.
I think the best inventions that changed the world most are:
lightbulb, electricity, telegraph, telephone, steam engine, television, camera, penicillin, computer, internet
