Thebottlegourd (葫芦) isanannualplantthatisamemberofthesa...

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The bottle gourd (葫芦) is an annual plant that is a member of the same family as melons. It is home to Africa and is believed to be one of the first plants grown by humans, thousands of years ago. Although it was occasionally used as a source of food or medicine, the bottle gourd was most valued for its hard-shelled dried fruit. Multi-functional bottle gourds were used by ancient people all around the world as floats for nets, containers for water and even as musical instruments. What botanists (植物学家) are unsure of, however, is exactly how the bottle gourds was at first transported from Africa to Asia and the New World.

The most usual theory is that bottle gourds simply drifted across the ocean, perhaps as an indirect result of African farmers transporting their crops by river. Bottle gourds are extremely able to float, so if any were to fall overboard during these trips, they were likely to be carried by the river to the open sea, where they would be swept away by ocean waves. Modern researchers have proven that the bottle gourd is able to stand such a journey, able to float in the ocean for hundreds of days and still carrying seeds from which new gourds can be grown.

There are others who believe that the bottle gourd was brought to the New World by African fishermen. The basis of this argument is that any naturally moving bottle gourds would have been washed up on New World beaches, an environment in which they do not naturally grow and then could not survive in. Therefore, humans had to have played a part in their appearance in the New World. Most botanists, however, argue against this theory. They believe those bottle gourds that floated across the ocean may have been carried inland by strong waves or hurricanes to more suitable ecological sites.

29. Why does the writer mention hard-shelled dried fruit?

A. To provide evidence that bottle gourds were planted.

B. To identify various values of bottle gourds.

C. To show how bottle gourds were used as medicine.

D. To explain why bottle gourds received so much attention from scientists.

30. Bottle gourds are used in the following ways except ________.

A. food B. medicine C. containers D. transport

31. The movement of the bottle gourds is explained by ________.

A. contrasting arguments put forward for natural and human movements

B. identifying the most common reason for their appearance

C. listing evidence that supports natural and human movements

D. explaining how sea life played a part in the process