The war made ______ impossible for the scientist to go on with his research.
| A．him | B．it | C．this | D．that |
It was decided to _____ the search when there was no hope of finding the missing girl alive.
| A．call off | B．take up | C．keep off | D．ring up |
The Prime Minister refused to comment on the rumor that he had planned to _____.
| A．discharge | B．dismiss | C．resign | D．resume |
Professor Jordon is well known for his _____ into the habits of the common housefly.
| A．examination | B．introduction |
| C．research | D．expression |
. I support your decision, but I should also make it clear that I am not going to be _____ to it.
| A．connected | B．fastened | C．bound | D．stuck |
John _____ knowledge of radio just by staying around the radio station.
| A．caught on | B．worked up | C．took up | D．picked up |