In the questionnaire, the subjects are questioned whether they____ no smoking in the public area.

--- You’ve left the water running. --- Oh, I have. _______ and turn it off.

Those who said looking after children was an easy way to make money obviously ______ such a troublesome boy, she thought

Over the past decades, sea ice _____ in the Arctic as a result of global warming.

In 1942，Columbus_______ on the of the Bahama islands, but he mistook it for an island off India.