As is known to all language learners, the newly learnt words will soon be forgotten unless they are _______ used in everyday communication.
| A．gradually | B．sincerely | C．hopefully | D．frequently |
It is believed to _____ over by sandstorms from AD 200 to AD 400.
| A．gradually cover | B．be gradually being covered |
| C．have been gradually covered | D．be gradually covered |
Many people are not fully aware of the damage that it does to their health. This is ____ we chose this picture as our logo.
| A．that | B．because |
| C．why | D．for which |
We want to shock people into ____ that many smokers die all too soon from illness and diseases _____ smoking.
| A．being realized; relating to | B．realizing; related to |
| C．realizing; relating and | D．being realized; related and |
George Gould too visited the tomb, ____ a high fever the next day.
| A．only to catch | B．caught |
| C．being caught | D．catching |
The best times to visit Shangri-la are spring and autumn ___ the temperature is at its mildest.
| A．where | B．on which |
| C．when | D．in that |