同学们做操，排成一个正方形的队伍，从前、后、左、右数，小红都是第5个，问一共有 ____ 人．

下图是某森林生态系统的食物网示意图，据图回答问题：

（1）该生态系统中，生产者是____ ，兔、狐等属于____ 。
（2）该食物网中共有____ 条食物链。
（3）该食物网中数量最少的生物是____ 。
(4）如果受到DDT污染，体内DDT含量最高的生物是____ 和____ 。
（5）写出其中4条食物链：____、 ____ 、____、 ____ 。

A

    A king loved music. One day, a man 1 the king a harp (竖琴). When the king played it,   the harp sounded terrible. Many people tried it. They agreed that the harp was useless. It was thrown out as rubbish.

    A little girl found the harp. She didn't know how to 2 it. She decided to have a try. She played day and night. The music was never perfect,  3 each time it sounded a little better.

    One day, the harp started to produce beautiful music. In fact, it was a 4 harp. It could be played well by someone if he put in enough effort (努力).

    The king called the girl to the palace. When he saw that she was playing the old harp. He was filled with joy. He made the girl his own private 5.