By the time John ________ to help, we ________ the work. A. comes / finished B. comes / will have finished C. will come / will have D. came / have finished90/100By the time John ________ to help, we ________ the work. comes / finishedcomes / will have finished will come / will havecame / have finishedGiải thíchChọn đáp án B