在如图所示的电路中，闭合开关，滑动变阻器的滑片P向左移动的过_爱下问搜题

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问题选择题

在如图所示的电路中，闭合开关，滑动变阻器的滑片P向左移动的过程中（两灯始终发光），则下列说法正确的是

A．电流表示数变小

B．灯L₁变亮，灯L₂变暗

C．电压表V₁的示数变小，电压表V₂的示数变大

D．电压表V₁的示数变小，电压表V₂的示数变小

答案

答案：D

题目分析：由电路图可知，灯泡L₁、L₂、滑动变阻器串联，电压表V₁测灯泡L₁、滑动变阻器两端的电压，V₂测灯泡L₂、滑动变阻器两端的电压，电流表测电路中的电流；滑片P向左移动的过程中可知滑动变阻器接入电路中电阻的变化，根据欧姆定律可知，电路中电流的变化，灯泡L₁、L₂两端电压的变化，灯泡亮暗的变化；进一步根据串联电路的电压特点可知两电压表示数的变化．

滑片P向左移动的过程，滑动变阻器接入电路中电阻变小，串联电路的总电阻变小；根据欧姆定律可知电路中电流变大，灯泡L₁、L₂两端的电压变大，所以灯泡L₂变亮；

由串联电路总电压等于各分电压之和可知，电压表V₁的示数为电源的电压减掉灯泡L₂两端的电压，电压表V₂的示数为电源的电压减掉灯泡L₁两端的电压，所以两点压表的示数都变小．故选D．

点评：本题考查了串联电路的特点和欧姆定律的计算，关键是电压表的正确使用和电路图串并联的识别。

单项选择题

下列工作内容，（）不属于劳动保障协理员为就业困难人员提供职业指导服务

A、技巧性指导

B、政策性指导

C、个性化指导

D、提高职业技能指导

问答题

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.

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.