Choose the option (A, B, C or D) that best completes each of the following sentences.
1. Mộc Châu Highland is the __________ of Vietnam.
2.The three Rs __________ reduce, reuse and recycle.
3. You shouldn’t throw those papers away; they’re __________.
4.We should use reusable shopping bags __________ plastic bags.
5. Thousands of people donated money and food to those in __________.
6. We should use __________ shopping bag to protect the environment.
7. Nowadays, people are using more __________ cosmetics.
8. My teacher asks us to __________ the amount of waste at school.
9. Plastic bags, bottles, papers should be put into recycling bins in order that they can be _____.
10. Air __________ is a serious problem that our city is facing due to our own activities.
