问题 问答题 论述题

论喷泉管道的布置要点。

答案

参考答案:

(1)主次管道的安排在小型喷泉中,管道可以直接埋在土中。在大型喷泉中,如管道多而复杂时,应将主要管道敷设在能通行人的渠道中,并在喷泉的底座下设检查井。只有那些非主要的管道,才可直接敷设在结构物中,或置于水池内。

(2)供水为了使喷水获得等高的射流,对于环形的配水管,多采用十字形供水。

(3)补充供水于喷水池内水的蒸发和在喷射过程中一部分水会被风吹走等,造成喷水池内水量的损失。因此,需在喷水池内设补充供水管。补充供水管除满足喷水池内的水量损失外,还应满足运行前水泵的补充水要求。如补充供水管直接与城市自来水相连接,则应在接管处设单向阀,以防污染城市自来水。

(4)泄水管水池的泄水管一般采用重力泄水,大型喷泉应设泄水阀门。小型水池只设泄水塞等简易装置。泄水管可直通城市雨水井,但要注意防止城市雨水倒灌,污染喷水池及水泵房等。

(5)溢水管水池的溢水管直通城市雨水管,其管径大小应为喷泉进水口面积的一倍。溢水管应有不小于0.03的坡度。在溢水口外应设有拦污栅。

(6)管径的一致连接喷头的水管,不能有急剧的变化,如有变化必须使水管管径逐渐由大变小,并在喷头前有一段长度适当的直管。其长度不小于喷头直径的20~50倍,这样以保持射流的稳定。

(7)应有自己的调节设备,一般用阀门或整流阀来调节流量和水压。

(8)清洗和检修为了便于清洗和检修,并从卫生和美观出发,喷水池每月应排空换水1~2次。在寒冷地区,为了防止冬季冻害等,所有的管道均应有一定的坡度,以便停止使用时,将管内的水全部排空。

(9)安装牢固喷泉管道的接头应紧密,设在结构物内的管道安装完毕后,应进行水压实验。并冲洗管道后再安装喷头。影响喷泉设计的因素较多,有些因素不易考虑。因此设计出来的喷泉,为了达到预期的艺术效果,应通过试验加以校正调整,以达目的。

解答题
写作题

第二节读写任务 (共1小题,满分25分)

阅读下面的短文,然后按照要求写一篇150词左右的英语短文。

Most high schools begin their day around 7:00 a.m., which leaves many teenagers nodding off in the morning. In fact, at least 20 percent of high school students fall asleep in class on a typical day. The problem: Teenagers need a lot of sleep-about nine hours each night, experts say. And most of them aren’t getting enough.

To help sleepy teens, some school districts of USA have tried delaying the opening of the high school day. The Minneapolis school district, for example, changed its start time from 7:20 to 8:40 a.m., giving its 12,000 high schoolers an extra hour and twenty minutes each morning.

Researches show that students in schools of these districts benefit a lot from the change. Students reported less depression when there was a later starting time. And teachers reported that students were more alert and ready for learning. Parents reported that their children were easier to live with because their emotions were more regulated.

Teachers especially wanted a change because they were concerned about student attendance and student readiness to learn that first period of the day. The change resulted in better attendance and less student sleeping in class that first hour.

[写作内容]

某英文学习报刊登了上述文章,并邀请读者就“高中生是否应该推迟上课”进行讨论。假设你是某校高三的学生李华,看了报道后,你打算联系自己的实际发表你的看法,内容要点包括:

1. 以约30词概括上述文章的内容;

2. 以约120词谈谈你的观点,并包括以下内容:

(1)你是否适应你校目前早上的上课时间;

(2)你是否赞成推迟高中早上的上课时间,并说明理由。

[写作要求]

1. 在作文中可以使用自己亲身的经历或虚构的故事,也可以参照阅读材料的内容,但不得直接引用原文中的句子;

2. 作文中不能出现真实姓名和学校名称。

[评分标准]

概括准确,语言规范,内容合适,篇章连贯。