Birds’singing is sometimes a warning to otherbirds________away.

The best way to deal with an impolite person is to _____ him. [ ]

volunteers are working for 2014 International Horticulture Exposition in Qingdao.

Modern forms of transportation and communication havedone much to ______ the isolationof life inAlaska.

Ms. La Rosa put forward ______ policy that not many teachers gave ______ second thought to at the conference.