Question 21. A. Some cities' authorities in the world have already implemented very strict lighting rules: outdoor lights must be fully shie...

Question 21.

A. Some cities' authorities in the world have already implemented very strict lighting rules: outdoor lights must be fully shielded so light doesn't go upward

B. This raises the question of whether it is important to put efforts into preserving the dark sky while cities continue to expand at a fast pace

C. In order to protect the dark sky from disappearing from the public's eyes, it is more important than ever to encourage cities to expand their areas

D. These efforts are crucial as increasing urbanization continues to worsen the problem, making dark sky preservation a global priority