She is an excellent student in our class, and she always ________ herself in her studies.
| A．hides | B．buries |
| C．covers | D．leaves |
The coat ________ thin but ________.
| A．is worn…is dried easy | B．wears…dries easily |
| C．has worn…has dried easy | D．wears…dries easy |
Food supplies in the earthquake area ________. We must act immediately before there’s none left.
| A．are being run out | B．are running out |
| C．have run out | D．have been run out |
No scientists can exactly figure out what ________ happened ________ at that time, which caused the extinction of the dinosaurs.
| A．on earth; on the earth |
| B．on the earth; on earth |
| C．on earth; on earth |
| D．on the earth; on the earth |
Experiments of this kind ________ in both the U.S. and Europe long before the Second World War.
| A．conducted | B．was conducted |
| C．had been conducted | D．had conducted |
-- Shall we take a taxi there since time is limited?
-- ________. It should be hard to get one during the rush hour.
| A．Go ahead | B．Don’t mention it |
| C．No doubt | D．Just forget it |