，hissuggestion is not helpful，though it sounds very interesting

(2013·湖北高考)An artist who was recently traveling on a ferry to the southern island discovered ________ a long lost antique Greek vase

To keep the air fresh during the night, I often sleep with the windows on ________ it’s really cold.

What are you reading, Mike? —I’m not really reading, just _________ the pages.

The police still haven’t found the lost child, but they’re doing all they ________.[ ]