2010年5月1日至20日的20天里,每天参观上海世博会的人数统计如下:(单位:

题型:解答题

问题:

2010年5月1日至20日的20天里,每天参观上海世博会的人数统计如下:(单位:万人次)

20,22,13,15,11,11,14,20,14,16

18,18,22,24,34,24,24,26,29,30

(1)写出以上20个数据的众数、中位数、平均数;

(2)若按照前20天参观人数的平均数计算,估计上海世博会期间(2010年5月1日至2010年10月31日)参观的总人数约是多少万人次?

(3)要达到组委会预计的参观上海世博会的总人数约为7000万人次,2010年5月21日至2010年10月31日期间,平均每天参观人数约为多少万人次?(结果精确到0.01万人次)

考点:平均数中位数和众数用样本估算总体
题型:解答题

女,10岁,咽痛、高热3d伴膝关节红肿、疼痛入院。查扁桃体红肿化脓,咽拭子经血平板培养出现无色透明溶血环,抗“O”试验阳性。引起感染的病原体可能是

A.甲型溶血性链球菌

B.金黄色葡萄球菌

C.乙型溶血性链球菌

D.肺炎链球菌

E.脑膜炎奈瑟菌

题型:解答题

急性血吸虫病血象检查显著增多的是()

A.中性粒细胞

B.白细胞总数

C.嗜酸性粒细胞

D.嗜碱性粒细胞

E.单核细胞

题型:解答题

如图所示,一个有界匀强磁场区域,磁场方向垂直纸面   向外.一个矩形闭合导线框abcd,沿纸面由位置1(左)匀速运动到位置2(右).则(  )                                       

A.导线框进入磁场时,感应电流方向为a→b→c→d→a

B.导线框离开磁场时,感应电流方向为a→d→c→b→a

C.导线框离开磁场时,受到的安培力方向水平向右

D.导线框进入磁场时.受到的安培力方向水平向左

题型:解答题

The teaching of English as a second language (ESL) in schools has had a history of conflicting arguments, interesting innovations and some very positive methodological changes. To understand the present situation, it is necessary to consider the past and the wider educational context which has a bearing on it.

Until quite recently, approaches to ESL work have been ply influenced by methods developed to teach English as a foreign language to older learners. These methods placed much emphasis on drills, exercises and remedial programs that focus on language in abstraction. 46) The prescriptive nature of such methods and the demands they made on the teacher’s time developed the belief that ESL work could be tackled only by the specialist ESL teacher working with small groups of children. Such an approach does not fit comfortably into current notions of learning and teaching in the primary school, nor does it sufficiently equip ESL learners in the secondary school to benefit from normal schooling. 47) In prescribing what language is to be taught, it has ignored what children bring to the learning task and the choices they make about how and what they want to learn. Furthermore, the location and organization of language provision did not measure up to the demand. 48) The language centers and English language services all contributed to providing special and concentrated teaching of English as a second language in small groups, varying in size from four or five to fifteen. Whatever the pattern of provision, the main aim was to give pupils sufficient English to enable them to join normal schools as quickly as possible. The success of such special provision depended very much on the close and constant liaison of language teachers with the subject teachers and the class teachers and on the continuity of learning experiences provided by them. 49) One of the important disadvantages of language centers and withdrawal groups was that ESL children were being taught away from those English- speakers who provide the most powerful models, i. e. their peer group. Peer-group interaction is an important element in any learning situation, but its particular strengths in a classroom with ESL learners cannot be overemphasized.

50) The separation of second language learners from the mainstream classroom cannot easily be justified on educational grounds, since in practice it leads to both their curriculum and language learning being impoverished.

49) One of the important disadvantages of language centers and withdrawal groups was that ESL children were being taught away from those English- speakers who provide the most powerful models, i. e. their peer group

题型:解答题

绘图题:画出中压电缆网开环运行的单环网接线图。

更多题库