25. C. After they had provided food, they cleared up the debris.
-> After + quá khứ hoàn thành, quá khứ đơn.
26. A. More tourists would come here if the beach were clean.
-> If 2: If + S1 + V2/ed, S2 + would + Vinf
27. B. Hung said that he liked studying at home on the internet.
-> câu trần thuật nên lùi thì
28. A. Lan will be learning English at 2p.m tomorrow.
-> at 2p.m tomorrow: tương lai tiếp diễn
29. C If the weather is nice tomorrow, we will go on a picnic.
-> If 1: If + S1 + Vs/es, S2 + will + Vinf
30. A to call ( need + to V )
31. B talking ( mind + Ving )
32. D being asked ( câu bị động với hate )