6. Christopher Columbus was the first person to navigate under the patronage of the Queen Isabella of Spain.

　　[A] explore [B] sail [C] work [D] circumvent

　　7. Immigrants entering the United States at the turn of the century often encountered living conditions radically different from those they had left behind.

　　[A] apparently [B] drastically [C] admittedly [D] tragically

　　8. Steel expands in hot weather, so suspension bridges may sag a foot more on a hot day.

　　[A] shrink [B] droop [C] bounce [D] rise

　　9. Many immigrants were prepared to work hard and in appalling conditions for the sake of their descendants.

　　[A] benefit [B] health [C] property [D] entertainment

　　10. Ships passing on the high seas exchange salutes by lowering and raising their flags once.

　　[A] information [B] ceremonies [C] greetings [D] privileges

　　Keys: 6-10 BBBAC