By how many percentage points has the clean air in China’s largest cities improved?

a. 3

b. 4

c. 5

d. 6

ANSWER: 4

Explanation:

Air quality in China’s largest cities continued to improve the first 6 months of 2016 according to the environment ministry of the country.

China’s largest 338 cities have experienced more clean air days in the first half compared with the same period of 2015.

76.7 percent of January to June days had clean air.

This is an increase of 4 percentage points from the earlier year.

In the capital city of Beijing, levels of PM 3.5 fell 17.9 percent from the earlier year.