________ by his brothers, he could continue his study in the university.
| A．Supporting | B．Supported |
| C．To support | D．Be supported |
-- You look so tired.
--- Yes. I _____ the house all the morning. But I’m finishing it soon.
| A．have cleaned | B．have been cleaning |
| C．have been cleaned | D．had been cleaning |
Police in America have stepped up their search for a fifteen-year-old boy who went _____ three days ago.
| A．going | B．losing |
| C．missing | D．disappearing |
There are _____ flights between the two cities, _____ it convenient for people in one city to travel to work in the other.
| A．regular; to make | B．usual; making |
| C．usual; having made | D．regular, making |
Though faced with so many difficulties, they are _____ about their future.
| A．curious | B．enthusiastic |
| C．optimistic | D．concerned |
The Sahara Desert is almost _____ of the US.
| A．as big | B．the size |
| C．the area | D．the same |