It is well understood _____ controls the flow of carbon dioxide in and out the atmosphere today.
| A．that | B．when | C．what | D．how |
Be __________. After all, he is a little boy.
| A．accurate | B．patient |
| C．neat | D．athletic |
Although difficult, she finished the job on time, so I think that she certainly deserved __________.
| A．being praised | B．to be praised |
| C．to praise | D．having praised |
The doctor suggested that he shouldn't __________ in bed for long.
| A．keep on lying | B．keep lying |
| C．keep to lie | D．keep lie |
So sudden __________ that the residents had no time to escape.
| A．was the earthquake | B．did the earthquake |
| C．the earthquake did | D．the earthquake was |
Scarcely had she heard the sad story when she __________ crying.
| A．burst into | B．burst out |
| C．broke out | D．broke into |