By "common resources" （Paragraph 2), the author means that ______.
A．the resources possessed by the United States should be shared by other countries
B．Americans have the right to consume resources both from their home country and from abroad
C．it is difficult to distinguish the resources possessed by America from those possessed by other countries
D．all the resources in the world should be shared by all the countries
A．role
B．subject
C．joke
D．supplement
According to the passage, the parity system is used to ______.
A．encourage farmers to produce more grains in the future
B．lower the cost of producing agricultural product
C．determine the prices below which grains will not be sold
D．ensure that the farmers' interest is properly protected
A．that
B．what
C．where
D．why
What does the word "disruptive" （Paragraph 3) most probably mean？
A．Naughty.
B．Rude.
C．Bad-mannered.
D．Careless.
A．when
B．why
C．where
D．whom