Although it was not named ________ 1782, this kind of metal was used as early as 5300 BC.A.in B.for C.until D.since
It is by no means clear ________ the president can do something to end the strike.
Good shoes, clothes and a backpack are the basic ________ you need for your hiking.
The Australian boy has a good ________ of Chinese and can express himself freely in it.
—How can I use the equipment? —Well, just refer to the ________.
—Do you know why Jane was so angry? —Her roommate gave in to ________ and opened the letter addressed to her.