III
1. wrote - haven't received
2. is raining - don't have
3. said - hasn't phoned
4. was repairing
5. didn't live
6. will be repaired
7. helping
IV
1. cultural : thuộc về văn hóa
2. effectively : hiệu quả
3. celebrations : dịp quan trọng
4. pollution : ô nhiễm
5. Deforestation : phá hủy rừng
V
1. helping - to help
2. keep _ be kept
3. forget - forgetting
4. to visit - visiting
5. than - to
