By the time he (return) home from England next month, they (already /build) a new house for him
2 câu trả lời
By the time he (return) returned home from England next month, they (already /build) had already built a new house for him
Đáp án
By the time + S+ V( QKĐ), S+ had+ ved|3
1 returned
2 had already built