C．became less satisfied with his own life

　　D．considered black as the ugliest color

　　解析：选C　推理判断题。根据文章第一段中的"A crow (乌鸦) lived in the woods and was satisfied with his life. But his life changed when he saw a swan (天鹅)．"可知，乌鸦原本对自己的生活很满意，但是当他看到洁白的天鹅后，他觉得自己的黑色羽毛没有白色羽毛漂亮，于是他对自己的生活没那么满意了，故答案选C。

　　5．The swan thinks the parrot is the happiest bird because the parrot .

　　A．has many colors

　　B．can fly around freely

　　C．attracts lots of people

　　D．has one more color than him

　　解析：选D　细节理解题。根据文章第二段中的"I thought that I was the happiest bird until I saw a parrot (鹦鹉), who has two colors."可知，天鹅认为鹦鹉是世界上最幸福的鸟，因为鹦鹉拥有两种颜色的羽毛，比天鹅多一种颜色，故答案选D。

　　6．What does the underlined part "our problem" in the passage refer to?

　　A．Comparing ourselves with others.

　　B．Feeling unhappy all the time.

　　C．Having less than others.

　　D．Having no freedom.

　　解析：选A　推理判断题。根据文章之前所讲的四种鸟之间的相互对比以及画线部分后面的"We make unnecessary comparison (对比) with others and become sad."可知，画线部分是指把自己跟别人进行比较，故答案选A。

　　7．By writing the passage, the author wants to tell us that .

　　A．there are more unhappy people around us

　　B．we should be happy with what we have

　　C．nothing is better than having freedom

　　D．beauty doesn't mean happiness

　　解析：选B　主旨大意题。根据文章末段中的"Learn to be happy with what you have ... the happiest in the world."可知，作者写本文的目的是想告诉我们应该知足常乐，故答案选B。