20．
A long time ago．there was an emperor．He had a beautiful garden．In the garden，there was a little nightingale（夜鶯） singing very beautifully．
One day the emperor heard about this little bird's beautiful voice．He asked his guards to bring her to him．As soon as the emperor heard the nightingale's voice，he said，"Put her in a golden cage，so she can stay and sing for me whenever I want to hear her．"
The little bird was so unhappy about being kept in the cage that she stopped singing one day．The emperor was very angry．He ordered the scientists in his palace to make a robot bird for him．The bird could sing very beautifully，too．The emperor was pleased．
Soon the robot bird became old．It no longer sang beautiful songs．Just at that time，the emperor became very weak．One morning，while lying in bed，the emperor wanted it to sing once again．But the robot bird couldn't sing any more．Suddenly the nightingale landed on the window．She began to sing her most beautiful song．The emperor was very happy!He became better and better each day．
After the emperor was well，he changed a lot and became kind to his people．From then on，all his people cherished（愛戴） him for his love and kindness．
56．Both the nightingale and the robot bird had a beautiful voice．T
57．The emperor kept the nightingale in a golden cage in order to hear her sing at any time．T
58．The nightingale was very happy after she was kept in the golden cage．F
59．The emperor was not satisfied with the robot bird at first．F
60．The emperor learnt from the nightingale what love and kindness was．T．
