. We should / shouldn't use ozone - friendly perfumes. • We should / shouldn't use private cars. • We should / shouldn't plant trees. • We should / shouldn't use animals in experi- ments. • We should / shouldn't cut trees. How many "should" and "shouldn't" can we choose? should shouldn't A A) 2. 3 B) 1 4 3 2 D) 4 1​