问题 填空题

阅读与思考题

         你了解实像和虚象吗    自从学习光现象以来,我们分别学习了实像和虚像,对于这两种像的区别与联系掌握起来却有点麻烦.实像是由实际光线会聚的,而且是倒立的,并且能用光屏承接;虚像是由实际光线的反向延长线会聚的因此不能用光屏承接,并且都是正立的;无论是实像还是虚像都能用眼看到.请根据上述信息回答一下问题:

(1)凸透镜能成_________

A.实像              

B.虚像              

C.实像和虚像          

D.无法确定

(2)透过放大镜可以看到物体被放大的虚像,关于放大镜的说法中正确的是_________

A.透过放大镜总能看到物体被放大的虚像

B.透过放大镜看到放大物体的虚像与物体在放大镜的同侧

C.物体距离放大镜越近成的虚像就越大

D.放大镜其实就是凹透镜

(3)下列现象中,只能成虚像的是_________

A.照相机照相              

B.平面镜成像

C.凸透镜成像              

D.小孔成像.

答案

(1)C;

(2)B;

(3)B.

单项选择题
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.assistance

B.guidance

C.confidence

D.tolerance