如果把向东行进10米作为+10,那么向东行-5米,实际是[ ]
A.向东行了15米
B.向西行了15米
C.向东行了5米
D.向西行了5米
答案:D
—We ______ talk loudly when we see the sign "Be quiet" on the wall.
—Yes, you are right. We should be polite in public.[ ]
A. must
B. mustn't
C. need
D. needn't
Our teacher told Simon _____ forget _____ the door. [ ]
A. not, to close
B. not to, to close
C. not, closing
D. not to, closing