如图，Rt△ABC的直角边BC在x轴正半轴上，斜边AC边上的中线BD反向延长线交y轴负半轴于E，双曲线y=$\frac{k}{x}$ （x＞0）的图象经过点A，若S_△BEC＝5，则k等于(         )

请根据句意从方框中选择合适的单词，并用其适当形式填空，使句子通顺。

(1)In the modern world, we should pay more attention to food. We should eat very ____ .
(2)Today is Children's Day. The children are enjoying ____ festival now.
(3)To support a big family, his father has to look for a ____  job besides delivering newspapers and milk.
(4)For your____ , you mustn't stand under the tree when it's raining in summer.
(5) Last month, Mrs Obama, U.S. First Lady, paid a week-long visit to China focusing on ____. She visited some schools and universities.

阳光下，一棵柳树所进行的生理活动有