老年人“耳背”，只有大声说话，才能勉强听清楚；其病变部位可能是（    ）

根据短文理解，选择正确答案。

    Disposing (处理) of waste has been a problem since humans started producing it. As more and more people choose to live close together in cities，the waste disposal problem becomes increasingly difficult.

    During the eighteenth century，it was usual for several neighboring towns to get together to select a faraway spot as a dump site. People would transport household rubbish，rotted wood and old possessions to the site. Regularly some of the trash was burned and the rest was buried. The unpleasant sights and smells caused no problem because nobody lived close by. Factories and some other industrial sites also had waste to be disposed of. Those located on rivers often just poured the unwanted remains into the water. Others built huge burners with chimneys to deal with the problem.

    Several facts make these choices unacceptable to modern society. The first problem is space. Dumps(垃圾场)， are most needed in heavily populated areas. Such areas rarely have empty land suitable. Farm areas are refusing to accept rubbish from elsewhere，cheap land in major city areas to dispose wastes is nonexistent(不存在的). Awareness of pollution dangers has resulted in more strict rules of waste disposal. Pollution of rivers，ground water，land and air is a price people can no longer pay to get rid of waste. The amount of waste，however， continues to grow.

    Recycling efforts have become commonplace，and many towns require their people to take part. Even the most efficient recycling programs，however，can hope to deal with only about 50 percent of a city's reusable waste，so more people should be involved in recycling programs.

如图所示的刻度尺的分度值为　 ____　，物体的长度记录为　 ____　cm．

阅读理解

A

　　　Many children enjoy riding roller coasters (过山车) because they like the exciting feelings a lot. They also like The Pirate Ship, Drop Tower, and Haunted House. But roller coasters are always the most popular for them in the park.

　　　The first modern steel roller coaster is the Matterhorn Bobsleds at Disneyland. It opened in 1959. The tallest roller coaster in the world is KingdaKa, in New Jersey, the USA. It is 456 feet (英尺) high. The world’s longest roller coaster is Steel Dragon 2000. It is in Japan. The fastest roller coaster is in Abu Dhabi. Its name is Formula Rossa, and it can reach 149 miles per hour.

　　　When we talk about roller coasters, safety (安全) is the most important thing we should think about. Modern roller coasters have built-in safety systems. Besides this, riders must do their best to follow all the safety rules so that we can ride roller coasters to get joy.