题干

在下面几种有关光的现象中,说法正确的是(   )

A:在水面的油膜上看到彩色条纹是光的干涉现象

B:光的波长比孔或者障碍物的尺寸小的多时,能发生衍射现象

C:对于单缝衍射,波长一定时,缝越窄,中央明纹越窄,且亮度越暗

D:观众要戴上一副特制的眼镜看立体电影是利用了光的偏振现象

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答案(点此获取答案解析)

A,B,D

同类题2

阅读下面短文,从短文后所给各题的四个选项(A、B、C、D)中,选出可以填入空白处的最佳选项。

    “Wanted: Violin. Can't pay much. Call …”

    Why did I notice that? I wondered, since I rarely looked at the classified ads. I laid the paper on my lap and closed my eyes, remembering what had happened during the Great Depression, when my family 1to make a living on our farm. I, too, had wanted a violin, but we didn't have the 2.

    When my older twin sisters began showing an interest in music. Harriet Anne learned to play Grandma's upright piano, 3 Suzanne turned to Daddy's violin, simple tunes soon became 4 melodies as the twins played more and more. 5 in the rhythm of the music, my baby brother danced around while Daddy hummed(哼唱)and Mother whistled. I just 6.

    When my arms grew7 enough, I tried to play Suzanne's violin. I loved the beautiful sound of the firm bow drawn across the strings. Oh, how I wanted one! But I knew it was 8 the question.

    One evening as the twins played in the school orchestra, I closed my eyes tight to capture the picture firmly in my 9. “Someday, I'll sit up there.” I vowed(发誓)10.

    Unfortunately, it was not a 11 year. At harvest the crops did not bring as much as we had hoped. I, however, couldn't 12 any longer to ask, “Daddy, may I have a violin of my own?”

    “Can't you use Suzanne's?”

    “I'd like to be in the orchestra, too, and we can't13 use the same violin at the same time.”

    Daddy's face looked 14. That night, and many following nights, I heard him 15 God in our family prayers, “… and Lord, Mary Lou wants her 16 violin.”

    One evening we all sat around the table. The twins and I studied. Mother sewed and Daddy wrote a letter to his friend, George Finkle, in Columbus. Mr. Frinkle, Daddy said, was a fine 17.

    As he wrote, Daddy read parts of his letter out loud to Mother. Weeks later I 18 he'd written one line he didn't read aloud: “Would you watch for a19 for my third daughter? I can't 20 much, but she enjoys music. And we'd like her to have her own instrument.”