Better English

1. It is widespread but not openly discussed. 2. progressive 
Here's a guide to the most confusing punctuation marks in the English language.
1. because it was the site of a major nuclear accident/because it was abandoned due to a nuclear incident 2. D 3. head to 
1. A 2. embargo 3. because of the establishment of the Frontier Closed Area/because of the closure of the border with China, which stopped cross-border trade 4. D
1. This year's exam was less stressful than last year's.  2. (i) number of schools surveyed (ii) number of schools that made all their Primary Three pupils sit the TSA this year
1. She decided to not follow what everyone else is doing. 2. C 3. B 4. adamant