Carbon dioxide(CO2)_______ from burning fuels is the most common of the so-called greenhouse gases.
| A．producing | B．having been produced |
| C．to be produced | D．produced |
Have you ever dreamed of staging a concert, ________ thousands of people are applauding and appreciating your music?
| A．at which | B．when |
| C．for which | D．which |
—How do you like the book?
—It's quite different from ________ I read last month.
| A．that | B．the one what |
| C．the one | D．which |
Suddenly I heard a man shouting at a driver, ________ car was blocking the street.
| A．which | B．whose |
| C．of whom | D．of which |
After visiting Harbin, most of the foreign friends said they would never forget the time ________ they had spent.
| A．that | B．what |
| C．when | D．at which |
Eleven people got killed in the accident, ________ the identities haven't been available.
| A．whose | B．of whom |
| C．to whom | D．with whom |