18.Ripe fruit is often stored in a place who contains much carbon dioxide so that the

A B C

fruit will not decay too rapidly.

D

19.In 1852,Massachusetts passed a law requiring all children from four to eighteen

A B C

years of old to attend school.

D

20.The main purpose of classifying animals is to show the most probable

A B

evolutionary relationship of the different species to each another.

C D

21.Matthew C.Perry,a United States naval commander,gained fame not in war and

A B C

through diplomacy.

D

22.One of the most impressive collections of nineteenth-century European paintings

A B

in the United States can be found to the Philadelphia Museum of Art.

C D

23.Three of every four migrating water birds in North America visits the Gulf of

A B C

Mexico's winter wetlands.

D

24.Charleston,West Virginia,was named for Charles Clendenin,who son George

A B

acquired land at the junction of the Elk and Kanawha rivers in 1787.

C D

25.Financier Andrew Mellon donated most of his magnificent art collection to the

A B C

National Gallery of Art,where it is now locating.

D

26.Soil temperatures in Death Valley,California,near the Nevada border,have been

A B C

known to reach 90of degrees Celsius.

D

27.When the Sun,Moon,and Earth are alignment and the Moon crosses the Earth's

A B C

orbital plane,a solar eclipse occurs.

D

28.Mary Cassatt's paintings of mothers and children are known for its fine linear

A B

rhythm,simple modelings,and harmonies of clear color.

C D

29.Plants synthesize carbohydrates from water and carbon dioxide with the aid of

A B

energy is derived from sunlight.

C D