----- Nội dung dịch tự động từ ảnh ----- He spent an hour revising what he had already learnt for the test. It takes him an hour to revise what he had already learnt for the test. O It took him an hour to revise what he had already learnt for the test. O It takes him an hour revising what he had already learnt for the test. O It takes him an hour revising what he has already learnt for the test.
