⑴Are you crying? A. No. My eyes hurt.
⑵How do we use wood? B. We should plant trees.
⑶What should we do to make the air clean? C. It's on 12th March.
⑷When's Tree Planting Day in China? D. Because we need it to keep us alive.
⑸Why is the air very important? E. We use wood to make beds.