问题 单项选择题

在使用多片DAC0832进行D/A转换、并分时输入数据的应用中,它的两级数据锁存结构可以().

(A)保证各模拟电压能同时输出

(B)提高D/A转换速度

(C)提高D/A转换精度

(D)增加可靠性

答案

参考答案:A

阅读理解与欣赏

阅读园地。

我的老师

  我最喜爱教英语的王老师,因为她最能理解我们的心情。记得五年级时有个转学来的陈晖同学,他对学英语毫无兴趣,很怕上英语课,连英语 26个字母都写不出。王老师很理解他的心情和学英语的难处,就着重辅导陈晖,并用一些形象的图片、例子来增强陈晖对单词和语法的记忆。每当陈晖掌握一种语法或一个单词,甚至一个字母,王老师就会当众表扬他。陈晖学英语的积极性高了。

  王老师不但理解我们,还善于引导我们。那是一次自习课上,她拿着试卷给我们评讲。正当讲得起劲的时候,忽然,从操场上传来“嗡嗡嗡”的马达声。怎么回事?同学们都忍不住伸长了脖子向外观看。原来,是自然老师在做牵引飞机试航。同学们希望去阳台看一看。顿时,教室里轻轻骚动起来。

  王老师见我们不在认真听讲,她先是一愣,露出疑惑的神情。当王老师转头看到自然老师在做模型飞机试航,回头又看到我们那充满期待的眼神时,才恍然大悟。她果断地一挥手说:“到外面去看看吧!”同学们都高兴地欢呼起来。

  回到教室,同学们一时还安静不下来。王老师就微笑着开了口:“你们很喜欢飞机吧。可要知道现在国外航天事业比我国强得多,这就需要学习更多的知识,而外语是学习研究国外先进技术的必要工具……”这时,教室里显得格外安静,大家又继续认真地听王老师评讲试卷。

  这样的老师怎不叫人喜欢呢?

1.联系上下文,解释句中加粗的词语。   

“回头又看到我们那充满期待的眼神时,才恍然大悟。”   

“期待”指的是________________________________,“恍然大悟”指的是__________________________

2.用“~~”与“____”分别从文中第4、5自然段中画出一句老师善于理解我们的句子和一句老师善于引导我们的句子。

3.文章用__________和________________两个事例来描写“我”喜欢的王老师,这两个事例是用_____________________________这句话连接起来的。

4.“我”喜欢的王老师是一个________________________________的人。

阅读理解

七选五

                                                            Crossroads International

     1. How does Crossroads work?

     Crossroads is a resource network.We take goods Hong Kong doesn't want and give them to people

who badly need them.We collect those goods and give them out in the welfare arena (福利院) in Hong

Kong, Mainland China, elsewhere in Asia, Eastern Europe and Africa. __  1____

     2. Who do we help?

     __   2    __  They are grassroot groups who have seen a need and tried to meet it.They can't get the

job done without backup, though, so our task is to help them do their task.Our warehouse is full of goods, from computers to high chairs, clothing to books, stationery to medical provision, cupboards to dining sets.They send us a list of their needs and we try to match it with the resource we have in stock.

     3.  __   3   __  

     Crossroads itself also operates on a low budget.We do not buy the goods we send.They are donated. __   4   __   Nobody in our organization receives a salary.Even our fulltime staff work on a voluntary

basis.

      Those that donate goods and services:

     ●Factories                       ●Manufacturers

     ●Hospitals                       ●Hotels

     ●Educational Institutions  ●Householders

     ●Transport Companies    ●Offices

     ●Other Charities

     __    5    __  While we receive large quantities of goods and there is never a short supply of requests

for them, we are always in need of hands to help sort and prepare them for shipping.

     A.One resource that we are always in need of is people.

     B.So Crossroads is just that: a Crossroads between need and resource.

     C.What can I do?

     D.The welfare agencies we help do not run on large budgets.

     E.How do we operate?

     F.All volunteer work is done at our warehouse.

     G.Similarly, rather than raising funds for freight (货运), we ask transport companies to donate their

services.