Unemployment in USA is to remain high in 2010, and possibly for the next few years.
| A．likely | B．necessary | C．gradual | D．normal |
There is no simple answer, _____ is often the case in science.
| A．as | B．that | C．when | D．where |
Finally he reached a lonely island _________ was completely cut off from the outside world.
| A．when | B．where | C．which | D．whom |
He wrote a letter ______ he explains what had happened in the accident.
| A．what | B．which | C．where | D．how |
The president of the World Bank says he has a passion for China, ______ he remembers starting as early as his childhood.
| A．where | B．which | C．what | D．when |
Happiness and success often come to those ________ are good at recognizing their own strengths.
| A．whom | B．who | C．what | D．which |