The oil must have been used up,______the light went out.A．becauseB．forC．sinceD．as

In cleaning up an oil spill, the use of straw or reclaimed paper fibers would be an exampl

Which of the following sentences expresses probability？A．He must have picked up a cold—he"

What is the outcome of the oil pipeline explosion？A．Attackers have been arrested by the po

The Johnsons must have been out, ___there is no light which can be seen in their house ton

There must have been someone who had informed the owner of the bathing center of the sudde

The translator must have an excellent up-to-date knowledge of his source languages full f