_________ is a growing world problem, and nowadays the United Nations and its member countries _________hard to deal with it．
| A．Desertification; are working | B．Desertified ; worked |
| C．Desert; work | D．Desertification; have worked |
You can’t use the machine today because some parts this week.
| A．are replaced | B．are being replaced | C．have replaced | D．are replacing |
The employee you have been thinking highly dishonest.
| A．of proving | B．of proves | C．of to prove | D．of being proved |
Though young, he succeeded in taking the machine skillfully and then put it together without any 
difficulty.
| A．out | B．down | C．apart | D．up |
There is no doubt the boxes were then put on a train for Konigsberg, was at that time a German city on the Baltic Sea.
| A．whether, which | B．that, where | C．that, that | D．that, which |
She__________ Robert for ten years.
| A．married | B．married with | C．has been marrying | D．has been married to |