1. Scientists say that exhaust fumes are___poisoning___ our city. ( poison)
(Câu này có are, sau are + Ving)
2. Many seabirds were___dead___ because of the oil spill. (die)
(sau were + tính từ; từ die không thể chia động từ Ving)
3. Waste from households will gradually ___contaminate____ the...