_____ we were worried about was _______ they could manage to control the pollution.
| A．That; how | B．That; whether |
| C．What; that | D．What; whether |
I _____ on a sofa because my grandparents have come for the weekend.
| A．slept | B．was sleeping | C．have slept | D．am sleeping |
I would rather buy a house in the suburb than ____ in the city.
| A．it | B．one | C．this | D．that |
He feels that his health ____ owing to ____ a long walk every other day.
| A．is improving; taking | B．has been improved; being taken |
| C．improved; taken | D．is improving; have taken |
Although John was the eldest in the family, he always let his sister _____ charge of the house.
| A．take | B．hold | C．make | D．get |
The island where these rare birdsnest has been declared a _____.
| A．observation | B．reservation | C．preservation | D．conservation |