Helen ___her keys in the office so she had to wait until her husband ___home. A. has left; comes B. left; had come C. had left; came D. had left; would come
【单选题】When I reach the school grounds there are lots of 'good mornings' _____ me _____ the boys, many _____ whom have walked a long way, sometimes up _____ two hours, to get to the school. [ ]