单项选择题
A．Break the top off. B．Use the mouth. C．Step by step. D．Put it on the floor.
A．New Yorkers are usually open with strangers. B．People from the South are usually considered good hosts. C．The friendliest Americans travel from place to place. D．Different parts have different customs and habits.
A．a great effect on everyone’s intelligence B．same effect on most persons’ intelligence C．some effect on a few persons’ intelligence D．no effect on most persons’ intelligence