Citric acid can be （）from the juice of oranges，lemons，limes or grapefruit.

单项选择题When King George（），his brother succeeded him on the throne.

A.abdicated
B.addicted
C.appointed
D.appraised

单项选择题His term of office （）at the end of June.

A.exchanged
B.expired
C.explained
D.exported

单项选择题The organization are （）food to the earthquake victims.

A.discharging
B.distributing
C.dismissing
D.disregarding

单项选择题Our force has been（）from the dangerous area.

A.accused
B.deposited
C.withdrawn
D.rectified

单项选择题He is universally recognized as an authority on construction engineering so one of his jobs is（）the building work.

A.supervising
B.publicizing
C.recruiting
D.applying