题目内容：

阅读下列短文，根据短文内容填空，在未给提示词的空白处仅填写1个适当的单词，在给出提示词的空白处用括号内所给词的正确形式填空。

Chocolate was first used as a drink over 3,500 years ago in 1. (center) America. It was very popular with the Mayans and the Aztecs. In fact, cocoa beans were very important to people there. That was 2. they were used as money. In the beginning, cocoa 3. (plant) in Ecuador, which was, for a long time, the world’s number-one producer of cocoa beans. It is still one of the top producers of the beans, but nowadays more than 70 per cent of cocoa beans come from West Africa.