An audience’s humorous words made us , so the lecturer couldn’t make himself .
| A．laugh; hearing | B．laugh; heard | C．laughing; hear | D．laughed; to be heard |
．Look! The dictionary, ________cover is red, is a birthday gift given by Tom．
| A．which | B．whose | C．its | D．where |
_______environmental damage is done, it takes many years for the ecosystem to recover．
| A．Even if | B．If only | C．While | D．Once |
．Every possible means _______to prevent the air pollution, but the sky is still not clear．
| A．are being used | B．have been used |
| C．has been used | D．had been used |
．______ surprised the family most was ________the girl played basketball very well．
| A．That; that | B．That; what | C．What; that | D．What; what |
．I have to see the doctor because I________a lot lately．
| A．cough | B．coughed |
| C．have been coughing | D．had coughed |