新老兵运输期间，同一硬座车厢载有（）名以上的老兵，车站和列车都不得发售该车厢的车票。

盐酸氯丙嗪与盐酸异丙嗪注射液的紫外分光光度法测定其含量时，测定波长不选用其最大吸收波长(254nm)，而分别选用306nm与299nm进行测定的原因在于

A．注射液中均加入抗氧剂，干扰测定
B．注射液中均加入助溶剂
C．注射液中均加入维生素C(λmax243nm)，干扰测定
D．注射液在λmax为254nm处吸收度不稳定
E．采用其λmax为254nm波长处测定吸收度使测定的灵敏度太高

阅读理解。

     It was the last day of the final examination in a college. On the steps of building, a group of engineering

students were waiting for the last exam. On their faces was confidence.

     They knew the exam would be easy. The professor (a teacher at a college) had said they could bring any

books or notes during the test.

     Right after they came into the classroom. The professor handed out the papers. There were only five

questions on it.

     Three hours passed. Then the professor began to collect the papers. The students no longer looked

confident. On their faces was nervous expression. The professor watched the worried faces before him, and

then asked, "How many of you have completed all five questions?" No hand was raised. "How many of you

have answered four?" Still no hands."Three? Two?" The students moved restlessly in their seats. "One, then?

Certainly somebody has finished one." But the class kept silent. The professor said,"That is exactly what I

expected. I just want to make you know clearly that even though you have completed four years of engineering.

There are still many things about the subject you don't know. These questions you could not answer are

common in everyday practice." Then, smiling, he added, "You will all pass this course, your education has just

begun."

     The years have obscured the name of this professor, but not the lesson he taught.

1. Why did the students think the exam was easy at first?

A. Because it was their last exam in the college.

B. Because they knew there were only five questions.

C. Because they thought they were clever and talented.

D. Because they were allowed to bring any books and notes during the text.

2. What does the underlined word "obscured" mean in the last paragraph?

A. 模糊

B. 回忆

C. 提醒

D. 改变

3. What could the students learn from the last exam?

A. He laughs best who laughs last.

B. A good beginning is half done.

C. One is never too old to learn.

D. The early bird catches the worm.

4. What's the best title for the article?

A. Some Confident Students.

B. An Engineering Exam.

C. An Interesting Professor.

D. An Unforgettable Lesson.

简答《通典》关于国家制度的新发展。

滚动轴承径向工作间隙太小不会导致润滑油膜层破坏而发生轴承高温烧附。