Scientists say it may be five or six years _______ it is possible to test this medicine on human patients.
| A．since | B．after |
| C．before | D．when |
Asia is the largest continent, ___ one third of the earth’s land area.
| A．to cover | B．cover | C．covering | D．covered |
After many months of hard work, they manager __ off all the debts.
| A．to pay | B．paying | C．paid | D．paying |
Mike is taller than __ students in the class.
| A．any | B．any other | C．all | D．everyone |
The little hero could be seen with his legs __ around the truck and his blond head __ out above the branches.
| A．wrapped, sticking | B．wrapping, sticking | C．wrapped, sticked | D．wrapping, sticked |
__ to get there before two, we set out earlier than before.
| A．So as to | B．In order | C．So that | D．In order that |