— Where is the hospital?
— It’s about 500 meters ______ the school.
| A．north of | B．in the north of |
C．the north of | D．in north of |
If by any chance someone comes to see me, ask them to leave a________.
| A．message | B．letter | C．sentence | D．notice |
The new law would come into ___on the day it was passed.
| A．effect | B．use | C．service | D．existence |
The doctors must get there in half an hour. There should be no____ in sending the blood to the dying girl .
| A．delay | B．wait | C．time | D．hurry |
.Among all the problems,_______is so difficult as this one.
| A．not one | B．either | C．neither | D．none |
It was 1920 ______ regular radio broadcasts began.
| A．while | B．when | C．that | D．since |