某同学通过实验测定半圆形玻璃砖的折射率n。如图甲所示，O是圆心_爱下问搜题

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问题单项选择题

某同学通过实验测定半圆形玻璃砖的折射率n。如图甲所示，O是圆心，MN是法线，AO、BO分别表示某次测量时光线在空气和玻璃砖中的传播路径。该同学测得多组入射角i和折射角r，做出sini-sinr图像如图乙所示。则（）。

A.光由A经O到B，n=1.5

B.光由B经O到A，n=1.5

C.光由A经O到B，n=0.67

D.光由B经O到A，n=0.67

答案

参考答案：B

解析：

由图线可知，可得n=1.5；因i是入射角，r是折射角，折射角大于入射角，故光由B经O到A，故选B.

考点：光的折射定律

完形填空

I often read of incidents of misunderstanding or conflict. I’m left   1 . Why do these people create mistrust and problems, especially with those from other   2 ?
I was growing up in Kuala Lumpur in the early 1960s, 3  children from different races and religions played and studied   4 in harmony. At that time my family lived a stone’s   5  from Ismail’s. And no one was bothered that Ismail was a Malay Muslim and I was an Indian Hindu—we just   6  our differences. Perhaps, our elders had not filled our heads with unnecessary advice, well   7  or otherwise.
We were nine when we became friends. During the school holidays, we’d   8 the countryside on our bicycles, hoping to   9  the unexpected. At times Ismail would accompany my family as we made a rare shopping trip to town. We would be glad of his   10 .
When I was twelve, my family moved to Johor. Ismail’s family later returned to their village, and I   11  touch with him.
One spring afternoon in 1983, I stopped a taxi in Kuala Lumpur. I   12  my destination. The driver acknowledged my   13  but did not move off. Instead, he looked   14  at me. “Raddar?” he said, using my childhood nickname. I was astonished at being so   15  addressed (称呼). Unexpectedly! It was Ismail! Even after two   16  we still recognized each other. Grasping his shoulder, I felt a true affection, something   17  to describe.
If we can allow our children to be   18  without prejudice, they’ll build friendships with people, regardless of race or religion, who will be   19  their side through thick and thin. On such friendships are societies built and   20  we can truly be, as William Shakespeare once wrote,“we happy few, we band of brothers”.

A．get through

C．come across

B．instructions

D．arrangements

C．disappointedly

单项选择题

颈动脉鞘由哪组筋膜形成（）

A.颈浅筋膜

B.颈深筋膜浅层

C.颈深筋膜深层

D.颈深筋膜中层

E.以上都不是