From the dates________on the gold coin,it is confirmed that it was made five hundred years ago.
We wonder ___________ quite a number of living things are dying out.
He was so busy that he couldn’t help ____________ the experiment.
After he ________ the golf club, he has ________ a number of competitions.
My uncle’s house is much smaller than ours, but it is twice expensive.
He seems to Jane. He knows her well.