（A） increased its circulation more than double since then，

　　（B） has since increased its circulation more than double，

　　（C） has since more than doubled its circulation

　　（D） since then more than doubled its circulation

　　（E） more than doubled its circulation since then

　　16. Unlike Gertrude Stein， Ezra Pound， and other expatriates， William Carlos Williams insisted that

　　poets honor their own regions and employ specifically American rhythms.

　　（A） Unlike Gertrude Stein， Ezra Pound， and other expatriates， William Carlos Williams insisted

　　（B） Although Gertrude Stein， Ezra Pound， and other expatriates did not， William Carlos Williams'

　　insistence was

　　（C） Contrary to Gertrude Stein， Ezra Pound， and other expatriates， it was William Carlos Williams who insisted

　　（D） As opposed to what Gertrude Stein， Ezra Pound， and other expatriates did， William Carlos

　　Williams was to insist.

　　（E） While Gertrude Stein， Ezra Pound， and other expatriates did not， William Carlos Williams

　　was insistent

　　17. Just as plant species native to regions with browsing mammals evolved many natural anti-

　　browser defenses （such as sharp spines and toxic chemicals）， so humans in malarial regions have

　　evolved dozens of chemical defenses against malaria.

　　（A） so humans in malarial regions have evolved dozens of chemical defenses against malaria

　　（B） humans in malarial regions have been evolving dozens of chemical defenses against malaria

　　（C） there has been， in malarial regions， an evolution of dozens of human chemical defenses

　　against malaria

　　（D） dozens of chemical defenses against malaria have been evolved by humans in malarial regions

　　（E） similarly， in malarial regions， humans have evolved dozens of chemical defenses against malaria

　　18. As virtually all the nation's 50 busiest airports are， New York's were built for an age of propellers，

　　before jet planes weighing 800，000 pounds needed over two miles of runway.

　　（A） As virtually all the nation's 50 busiest airports are

　　（B） As with virtually all of the nation's 50 busiest airports

　　（C） Like virtually all of the nation's 50 busiest airports

　　（D） Like the cities where virtually all the nation's 50 busiest airports are

　　（E） Like other cities where virtually all the nation's 50 busiest airports are