本地区常用的砖、毛石（片石）、砂浆的强度等级是多少？

导游服务作为旅游产品的组成部分，已经成为旅游经营的一项重要内容，这体现了（ ）。

A．导游职业自由化

B．导游服务专业化

C．导游服务商品化

D．导游服务规范化

植物细胞具有而草履虫没有的细胞结构是（　　）

A．细胞壁

B．细胞膜

C．细胞质

D．细胞核

锯轨作业要求：锯断后的钢轨，上下截面偏差不大于（）。

A.0.3mm

B.0.5mm

C.1mm

D.1.5mm

短文二：① 春天必然曾经是这样的。在《诗经》之前，在《尚书》之前，在仓颉造字之前，一只吃草的小羊猛然感到草的多汁，一个放风筝的孩子猛然感到风筝的飞腾，一位患 风痛的老人猛然感到腿的舒活，一位溪畔浣纱的女子猛然感到手的温润……人们不由自主地将嘴噘成吹口哨的形状，惊喜地奔走互告：“春！”② 春天必然曾经是这样的。在绿意内敛的山头，一把雪再也撑不住了，噗嗤的一声，将冷脸笑成花面，一首澌澌然的歌便从云端唱到山麓，从山麓唱到低低的荒村，唱 入一只小鸭的黄蹼，唱入软溶溶的春泥，软如一床翻新的棉被的春泥。那样娇，那样敏感，却又那样浑沌无涯。一声雷鸣，可以无端地惹哭满天的云；一阵杜鹃啼， 可以逗急一城杜鹃花；一阵风起，可以唤出漫天的柳絮。反正，春天就这样不讲道理，不讲逻辑，而仍可以好得让人心平气和。③满塘叶黯花残的枯梗抵死枯守一截老根，北地里千宅万户的屋梁受尽风欺雪扰犹自温柔地抱着一团小小的空虚的燕巢。然后，忽然有一天，桃花把所有的山村水郭都攻陷了，柳树把皇室的御沟和民间的江头都控制住了。春天有如旌旗鲜明的王师，因长期虔诚地企盼祝祷而美丽起来。④ 鸟儿开始丈量天空了，有的负责丈量天的蓝度，（　　　　　　　　），有的负责蚊量天的透明度。所有的鸟儿全不是好的数学家，它们叽叽喳喳地算了又算，核了 又核，终于还是不敢宣布统计数字。至于艳丽的花，已交给蝴蝶去点数；芬芳的蕊，交给蜜蜂去编册；葱郁的树，交给黄鹂去吟唱；而轻柔的风，交给风铃去垂询， 去记忆。春天必然曾经是这样的，或者，在什么地方，它仍然是这样的吧。穿越烟囱与烟囱的黑森林，我想走访那踯躅在湮远年代的春天。【注】作者张晓风，原文有删改。

根据上下文的句式和语意，给④自然段横线处补写一个恰当的句子。（请将答案写在下面的横线上。）

阅读理解。

      This was no ordinary class. The students who came together were all science or engineering professors

at Cornell University. They had interrupted their research to accept an invitation to take part in an unusual

experiment:"an interesting week of poetry." This class was part of a study to answer the questions: Why is

science difficult for many nonscience students? What can teachers learn about teaching if they take a class

that is not in their field?

     The students in the poetry class listened to lectures and took notes. They had reading tasks and had to

write three short papers. All students noticed one thing-the importance of spoken words. In science and

engineering classes, the instructors put tables and drawings on the blackboard. But in this poetry class, the

instructors just talked. They didn't write anything on the board.

     The scientists and engineers noticed one similarity between science and poetry. In both subjects, students

need to find layers (层次)　of meaning. Some layers are simple, clean, and on the surface; other layers are

deeper and more difficult. This search for different levels of meaning doesn't happen much in undergraduate

(本科)　science classes, but it is important later, in graduate school. And it is always important in humanities (人文科学).

     Both the poetry instructors and their students learned something about teaching from this experience.

One poetry instructor, for example, now sees the importance of using informative as he teaches. Most of the

scientists agreed on several points. First, humanities classes might help science students to see patterns and

decide which information is important. Second, the poetry class was fun. One engineer decided, "We need to

change the way we teach engineering to make it an enjoyable experience for students."

     But perhaps the most important result of the experience was this; All of the professors began to think

about how they teach and how they cam teach better.

1. What do we know about this unusual class?

A. The teachers did lots of writing on the board.

B. The teacher were invited to attend several lectures.

C. The student were professors from a university.

D. The students were studying science and humanities.

2. The experiment was designed to find out _____.

A. how to teach the students in the science class.

B. whether poetry is difficult for science students.

C. what to be taught in the humanities class.

D. why many humanities students find science hard.

3. Finding levels of meaning is _____.

A. important for graduate students in humanities.

B. difficult for graduate students in humanities.

C. common for undergraduate students in science.

D. easy for undergraduate students in science.

4. What did the science professors learn after the experiment? 

A. They should change the way they teach .

B. A poem could be explained in clear definitions.

C. A poetry class could be more informative.

D. Their teaching was an enjoyable experience.