-----Did you find the missing couple in the mountain yesterday?
-------No, but we _ to get in touch with them ever since.
A have tried
B. had tried
C. have been trying
D. had been trying
John _____ knowledge of radio just by staying around the radio station.
| A．caught on | B．worked up | C．took up | D．picked up |
The _____ of his clothes indicated too clearly that he had been playing football.
| A．state | B．condition | C．occasion | D．situation |
When the entire class worked together they finished the project _____.
| A．in no way | B．in no time |
| C．on no account | D．in no case |
Paper making began in China and from there it _____ to North Africa and Europe.
| A．sprang | B．spilled | C．carried | D．spread |
Children who are over-protected by their parents may become _____.
| A．hurt | B．spoiled | C．damaged | D．harmed |