I. Choose the best option to complete each sentence. Circle A, B, or C. (1pt )
 1. Environmental pollution has ___________ to lots of health problems.
A. caused B. led C. made
2. ___________ industrial waste, many fish cannot survive.
A. Because B. Since C. Because of
3. Oil spills from cargos and ships have ___________ many animals and plants die.
A. made B. caused C. resulted
4. This film is rated 18  because there are too many ___________ scenes.
A. funny B. violent C. entertaining
II. Complete the sentence with the corect form of adjective : (2,5pt)
1. He is (clever) ………the clevest……………. student in my group. 
2. She can’t stay (long) …………longer………….than 30 minutes.
3. It’s (good) ………the best……………. holiday I’ve had.
4. The red shirt is better but it’s (expensive) …………more expensive…………. than the white one. 
5. I’ll try to finish the job (quick).……quickly……………….
6. Being a firefighter is (dangerous) ………more dangerous……………. than being a builder.
7. Lan sings ( good ) ……better…………..than Hoa
8. This is (exciting) …………most exciting…………. film I’ve ever seen.
9. My Tam is one of (popular) ………popular……………. Singers in my country.
10. Which planet is (close) ………the closest……………. to the Sun?