We can never expect_______bluer sky unless we create_______less polluted world.
| A．a; a | B．a; the | C．the; a | D．the; the |
China’s public dancers, often _____ as tiaowu dama, have found themselves at the center of a public debate in recent months.
| A．referring to | B．having referred to |
| C．referred to | D．being referred to |
But if a treatment ________ delayed the disease by seven years were to be available, the number of sufferers would drop by 40% by the middle of the century.
| A．where | B．when |
| C．why | D．that |
Cathy spent her summer vacation in reviewing her lessons _____ she would achieve marks in the coming examination.
| A．now that | B．as if |
| C．only if | D．so that |
The artist ________ the last years of his life here and FrancoisⅠacquired that masterpiece that even today represents one of France’s treasures: the Mona Lisa.
| A．lived through | B．lived out |
| C．lived up to | D．lived on |
Surely you shall not come into the study ________ I swore to devote myself to settling the problem, unless permitted.
| A．for which | B．in which |
| C．on which | D．with which |