A new notice should be put up to __________ the unwanted visitors __________.
| A．keep; in |
| B．keep; on |
| C．keep; up |
| D．keep; out |
With the living expense increasing rapidly, I, a fresh clerk in a company, have to take three part-time jobs, which _____ about extra $ 4,000 a year．
| A．bring in | B．take in | C．get in | D．put in |
Most of us think of games as child* s play, but games _____ children' s thinking and develop skills like problem solving and communication．
| A．sharpen | B．seize | C．adore | D．apply |
In a courtroom it is sometimes difficult to ______ who is innocent and who is guilty．
| A．distribute | B．develop | C．design | D．distinguish |
Future will be a marvelous world of artificial ______----- robots might have their emotions and we human beings might have robots as friends．
| A．preference | B．intelligence | C．exhibition | D．communication |
As second-hand smoking is more harmful and dangerous, people want a total _____against smoking in public．
| A．ban | B．brake | C．breakthrough | D．boundary |