Unit 3 A healthy life grammar课时作业

第一节(共10小题；每小题2. 5分，满分25分)

阅读下列短文，从每题所给的A、B、C和D四个选项中，选出最佳选项。

When a Swedish ship that sank in 1628 was recovered from the port of Stockholm，historians and scientists were overjoyed with the chance to examine the remains of the past. The ship construction showed how ships were built and operated during the seventeenth century. In this way，artifacts(史前古器物)，objects made by human beings，provided a picture of daily life almost 400 years ago.

Underwater archaeology-the study of ships，aircraft(航空器)and human settlements that have sunk under large bodies of water-is really a product of the last 50 years. The rapid growth of this new area of study has occurred because of the invention of better diving equipment. Besides the Swedish ship wreck(残骸)，underwater archaeologists have made more exciting discoveries such as the 5,000­year­old boats in the Mediterranean Sea.

Underwater archaeology can provide facts about the past. In ancient ports all over the world are ships sunk in the past 6,000 years. There are also sunken settlements in seas and lakes telling of people's way of life and their systems of trade in ancient times. Underwater archaeologists want to study these objects to add to the world's knowledge of history，but they have to fight two enemies. One enemy is treasure hunters who dive for ancient artifacts that they can sell to collectors. Once sold，these objects are lost to experts. The second enemy is dredging machines(挖掘机) often used to repair ports. These machines destroy wrecks and artifacts or bury them deeper under sand and mud. By teaching the public about the importance of underwater "museums" of the past，archaeologists are hoping to get support for laws to protect underwater treasures.

1．What purpose does Paragraph 1 serve in the passage?

A．To provide background information of the topic.

B．To attract readers' attention to the topic.

C．To use an example to support the topic.

D．To offer basic knowledge of the topic.