The flu is believed________by virus that likes to reproduce in the cells inside the human nose and throat.
| A．causing | B．being caused | C．to be caused | D．to have caused |
Many athletes are clear that the Olympic Games are the only time ________ they will be watched by thousands of millions.
| A．that | B．which |
| C．where | D．when |
The old man often looked back on the past days ________ he worked hard to make a living.
| A．which | B．when |
| C．where | D．that |
Recently I have bought an iPad 3 on the website of taobao. com, ________ the price is very reasonable.
| A．on which | B．in which |
| C．of which | D．from which |
Have you ever seen any trees ________ leaves were black because of the polluted air?
| A．whose | B．that |
| C．which | D．who |
The scientist won the Nobel Prize in Chemistry, ________ made him famous all over the world.
| A．this | B．that |
| C．what | D．which |