Here are the suggested sentences for the dialogue to fill in the blanks:

Mike: Do you think Ho Chi Minh City will be a good place to live in 2050?
Phong: (37) **I’m not really sure about it.** But I believe that it will be better than now.
Mike: (38) **What makes you think like that?**
Phong: Well, although it’s now an overcrowded city with lots of traffic jams and pollution, there are plans to improve the situation.
Mike: (39) **They will promote advanced technology to make greener motorbike.**
Phong: They will build smart underground transport networks. The city will no longer be full of cars.
Mike: Anything else?
Phong: (40) **What’s more, they are growing more trees and encouraging people to use solar panels.**
Mike: Sounds great! I hope their plans will come true and Ho Chi Minh City will become a more livable place.

Feel free to ask if you need any more help!