The government has promised to do ________lies in its power to ease the hardships of the victims in the flood-stricken area.
句意：政府已经承诺会尽一切能力来减轻洪灾地区灾民的困难。这里do 后而缺少宾语， lie in 前面缺少主语，whatever引导一个宾语从句做主句的宾语，并在从句中充当主语，相当于anything that，意为“政府能做的事”。