1. My sister, who always does her homework before going to class, is a hard-working student.
2. The exact time of the match hasn't been decided yet. (Câu BĐ thì HTHT: S + have/has been + P2)
3. He wishes he could speak English well. (câu ước ở hiện tại: S + wish + S + V_quá khứ đơn)
4. Mary enjoyed walking in the rain.