Here are the answers for the blanks based on the context of the questions:

Question 36: The **B. green space** can help make cities more sustainable and livable.

Question 37: The **A. public transport** is essential for daily commuting in large cities.

Question 38: Many people use **A. recycling program** to manage waste and reduce environmental impact.

Question 39: The **B. green space** can help make a city more sustainable and livable.

Question 40: The **A. city authority** helps people to be aware of city regulations and services.

Question 41: **A. Traffic safety** is important for ensuring that streets are safe for pedestrians.