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问题 选择题

从A={a1，a2，a3，a4}到B={b1，b2，b3，b4}的一一映射中，限定a1的象不能是b1，且b4的原象不能是a4的映射有（　　）个．

A．12

B．13

C．14

D．16

答案

a1的象不能是b1，分两种情况：

①a1的象是b4，a4的象有3种选择，其它两个元素的象分别有2和1选择，共3×2×1=6；

②a1的象不是b4，有两种选择，a4的象也有2种选择，其它两个元素的象分别有2和1选择，

共2×2×2×1=8．

∴总计6+8=14．

故选C．

单项选择题 A1/A2型题

苯巴比妥治疗新生儿生理性黄疸的机制主要是（）。

A.使Y-蛋白合成减少

B.使Z-蛋白合成增加

C.肝细胞摄取胆红素能力增强

D.使Y-蛋白生成增加

E.抑制葡萄糖醛酸转移酶的生成
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单项选择题

Teachers need to be aware of the emotional, intellectual, and physical changes that younga-duhs experience. And they also need to give serious (91) to how they can best (92) such changes. Growing bodies need movement and (93) , but not just in ways that emphasize competition. (94) they are adjusting to their new bodies and a whole host of new intellectual and emotional challenges, teenagers are especially self-conscious and need the (95) that comes from achieving success and knowing that their accomplishments are (96) by others. However, the typical teenage lifestyle is already filled with so much competition that it would be (97) to plan activities in which there are more winners than losers, (98) , publishing newsletters with many student-written book reviews, (99) student artwork, and sponsoring book discussion clubs. A variety of small clubs can provide (100) opportunities for leadership, as well as for practice in successful (101) dynamics. Making friends is extremely important to teenagers, and many shy students need the (102) of some kind of organization with a supportive adult (103) visible in the background.
In these activities, it is important to remember that young teens have (104) attention spans. A variety of activities should be organized (105) participants can remain active as long as they want and then go on to (106) else without feeling guilty and without letting the other participants (107) This does not mean that adults must accept irresponsibility. (108) , they can help students acquire a sense of commitment by (109) for roles that are within their (110) and their attention spans and by having clearly stated rules.

A．care

B．nutrition

C．exercise

D．leisure
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