past few years, sea ice ____ in theArctic as a result of global warming.

How long ______ you ______ —For five years. We ______ in 2001.

Bring your camera with you, you may want to takes some photos of the autumn trees.

They want to make _______ clear to the public that they are doing an important and necessary job. [ ]

The police ________ the lost child and tried to find his parents.