Exercise 5: Choose the best answer to complete the sentences.
1. The river water is severely polluted, mostly________ the dumping of raw sewage.
A. due to                  B. lead to         C. because       D. so
2. Sudden changes in water temperature can ________ mass killings of fish, plants, or amphibians.
A. come up              B. result in       C. dump into     D. thank to
3. Water pollution________ the death of all forms of life in the water bodies.
A. occurs                 B. results of     C. creates         D. leads to
4. ________ plastic takes so long to break down, it pollutes the land and ocean.
A. Because             B. Due to         C. Even if          D. Although
5. Many flights were cancelled ________ the smoke from forest fires.
A. so                       B. because      C. because of    D. result in
6. ________the garbage dump smells terrible, no one lives around there.
A. Because of        B. As                 C. Due to           D. Even though
7. ________the grain consumption is rising, forests will be cut to provide more room for planting crops.
A. since                 B. Although       C. unless            D. Due to
8. Grace didn’t love nature, ________ she wasn’t happy when her group went camping in a jungle.
A. but                    B. and               C. because         D. so
9. Thousands of fish were killed ________ a discharge of poisonous Chemicals from a nearby factory.
A. because           B. lead to           C. result in           D. as a result of
10. ________the fog, there were no take-oils from the airport yesterday.
A. Since               B. Because        C. Owing to         D. Thanks to