In crowded places like airports and railway stations, you __________ take care of your luggage.
| A．can | B．may | C．must | D．will |
Don’t you know ______, my dear friend, it is you that she loves?
| A．who | B．which | C．that | D．what |
She was so angry and spoke so fast that none of us understood ______ he said meant．
| A．that | B．what | C．that that | D．what what |
What will people die of in 100 years? If you think that is a simple question, you ______ attention to the revolution taking place in biotechnology．
| A．have not been paying | B．had not been paying |
| C．were not paying | D．will not be paying |
The girl wearing a pair of dark glasses comes from a city in South China, ______ is evident from her accent．
| A．who | B．that | C．where | D．as |
It was not until I was injured in a car accident ______ the real American society．
| A．that I found out | B．when I found out |
| C．did I find out | D．that did I find out |