阅读短文，下列问题

    People in many countries are learning English.Some of them are small children. Others are teenagers. Many are adults. Some learn at school, others learn by themselves. A few people learn English by hearing the language over the radio, on TV or in films. As we know, it's hard to learn a foreign language well. One must work hard to learn another language. Because we can't use it often. But if you have right ways to learn English, it's a piece of cake.

    Why do all these people want to learn English?It is difficult to answer this question. Many boys and girls learn English at school because it is one of their subjects required (要求) for study. They study their own language, math and English. Some people learn it because it is useful for their work. Many people learn English for their higher studies,because at colleges or universities some of their books are in English. Some people learn English because they want to read newspapers or magazines in English.

根据短文内容选择正确答案。

已知方程 可以配方成 的形式，那么 的值是（    ）

昆曲没落的主要原因是

①尊重              ②欺骗            ③信任             ④虚伪

用一副三角尺，你能画出下面那个度数的角（　　）