8) 4. a
5. b
6. a
7. b
8. b
9. a
10. b
9) 2. June is warmer than September.
3. Elephants are bigger than monkeys.
4. A giraffe is taller than a seal.
5. It is colder in winter than in summer.
10) must- listen to the teacher, answer questions, wear uniform, be quiet in the library.
mustn't- eat at lessons, throw rubbish, use your mobile, run during the break.