Question

4 the lights out program asks owners of tall office buildings to turn off lights at night, especially during the migration seasons. the program is based on one that began in toronto, canada, in 1993. since then, more than 20 big cities in north america have adopted lights out. it works! a study of just one chicago skyscraper showed that bird deaths decreased by 80 percent when lighting was turned off. question: which sentence best expresses the main idea of paragraph 4? a. turning off lights makes buildings look dark and unsafe. b. the lights out program has been unpopular in most major cities. c. turning off lights at night greatly reduces bird deaths during migration seasons. d. toronto banned all tall buildings after the program began in 1993.

Explanation:

The paragraph introduces the Lights Out program (turning off lights at night, especially during migration seasons), its origin, adoption in many cities, and a study showing a significant reduction (80 percent) in bird deaths when lights are off. Option C directly aligns with the main idea of the positive impact (reducing bird deaths) of turning off lights during migration seasons. Option A is incorrect as there's no mention of buildings looking dark and unsafe. Option B is wrong because more than 20 big cities have adopted it (so it's not unpopular). Option D is false as there's no mention of banning tall buildings.

Answer:

C. Turning off lights at night greatly reduces bird deaths during migration seasons.