You never imagine what trouble I have had ______ your house．It took me nearly 2 hours．

"We can not afford limited progress. We need rapid progress," Ban said at the Third World Climate Conference in Geneva,        by the World Meteorological Organization (WMO).

________in a heavy traffic jam in a taxi while you are hurrying to the airport is quite an unpleasant experience．

(2011·天津高考)Passengers are permitted______ only one piece of hand luggage onto the plane.

The thief took off his shoes when he slipped into the house in order to steal something ___.