题目内容
（请给出正确答案）
[单选题]
All guests are required to carry their original passport and room card when they leave the ship.
A.所有的游客在登船时应该主动出示身份证。
B.所有旅客在离船时需携带护照原件和房卡。
C.所有客人在离船前要仔细核对护照和房号。
提问人：网友lixin080108
发布时间：2022-01-07
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There would probably have been other successful commercial growers before Fish if Florida had not been under Spanish rule for some two hundred years. Columbus first brought seeds for citrus trees to the New World and planted them in the Antilles. But it was most likely Ponce de Le6n who introduced oranges to the North American continent when he discovered Florida in 1513. For a time, each Spanish sailor on a ship bound for America was required by law to carry one hundred seeds with him. Later, because seeds tended to dry out, all Spanish ships were required to carry young orange trees. The Spaniards planted citrus trees only for medicinal purpose, however, they saw no need to start commercial groves because oranges were so abundant in Spain.
What is the main topic of the passage?
A．The role of Florida in the American Revolution
B．The discovery of Florida by Ponce de Le6n in 1513
C．The history of the cultivation of oranges in Florida
D．The popularity of Florida oranges in London in the 1770's
