美国1787年宪法规定:“合众国不得授予任何贵族爵位，凡是在合众国担任受益职务……非经国会同意，不得从任何国王、君主或外国接受任何种类的……官职或爵位。”这一规定旨在（    ）

    English class is always full of fun. It's a tradition to put on an English play at the end of the year. Yesterday our English teacher gave us copies of the play.

    "Choose a character in the play whom you'd like to be," she told us. "This afternoon you will learn a few lines (台词) of this part for homework. Then tomorrow you can say those lines in front of the class. I'll decide who plays each part."

    I wanted to have one of the biggest parts in the play, so I chose the part of the king. He has a lot of lines to say. I learnt them by heart.

    This morning in our English class we had to say our lines. I acted the part of the king. When l was saying my lines, I put a lot of expressions into my acting. I thought I acted really well.

    Many of the students in my class couldn't act at all. They couldn't even read without making lots of mistakes. I was sure that l would get a big part in the play.

    However, the teacher gave me the part of a soldier. He has only one line. It is, "Yes, sir!"

    I was very disappointed. At the end of the lesson I went up to her and asked her why I had such a small part.

    "You put too many expressions in your acting," she said. "Good acting is not big acting. It is acting the audience can believe in." I think I know what she means.

    We think that life in Chinese high school is an adventure in which we have to survive mountains of homework and all kinds of exams. Yet would it be____(surprise) if I tell you that high school life in the US is almost as stressful and demanding as it is in China?

    In US high school, everything____(record) into your studying document, including your grades on quizzes, tests and final examinations. Failing____(turn) in your homework on time will directly affect your grade for a certain course. Perhaps contrary to____we used to think of the US high school students, they pay more attention to their____(academy) performance to try to get into a distinguished university.____, they'll be disappointed after graduation from high school.

    Like university students, US high school students have the____(free) to choose the courses that most interest____(they). Even a ninth grader can sit____the same classroom as twelfth graders. But this also means he or she has to work very hard, because the teacher will not treat him or her differently just because he or she is a few years____(young).

已知曲线y=$\frac{x^2}{4}$-3lnx的一条切线的斜率为$\frac{1}{2}$，则切点的横坐标为(     )

阅读下面一段文字，完成文后题目。
         ①八达岭长城驰名中外。②这里有崇山峻岭、xuányá 峭壁。③由于保存原始，八达岭长城不但残缺，而且雄风犹在。④那断壁残垣，在            A（白驹过隙∕斗转星移）、晨昏更替之间，默默地讲述着历史的cāngsāng。⑤八达岭古长城自然风光无限，“杏花坡”每临春季花团锦簇，姹紫yānhóng；“荆花谷”到了夏天便汇成蓝色的海洋……它们环衬着残长城，它们守护着古长城！