单项选择题
After years of efforts，those originally （）hills are now covered with young trees.
A.emptyB.bareC.hollowD.naked
单项选择题 He （）a plow superior to any other in existence.
单项选择题 Prices of fish （）from two to five yuan a kilo.
单项选择题 He （）his tie as soon as he walked out of the office building.
