The conference the_____ possibility of closer trade links.

 In this park , sparrows often fly down from trees to eat from visitors’hands. They are used to         in this way .

________ the housing price, several measures have been adopted in the last two years.

It was so cold that he had the fire ___________ all night long.

The Chinese mainland has 157 billionaires as of 2013，_________second in the number of billionaires worldwide．