问题 单项选择题 B1型题

成牙本质细胞的胞浆突形成()。

A.绞釉

B.釉丛

C.釉梭

D.釉柱横纹

E.釉质生长线

答案

参考答案:C

解析:

釉梭是起自釉牙本质界而伸向釉质的纺锤状结构,为成牙本质细胞突起的末端膨大,穿过釉牙本质界并埋在釉质中,故1题选C。釉柱横纹是釉柱上与长轴相垂直的细线,与成釉细胞每天的周期性形成釉质有关,代表每天釉质形成的速度,故2题选D。釉柱从釉牙本质界至牙表面的行程近表面1/3较直,内2/3弯曲,称为绞釉,增强了釉质对咬合力的抵抗,故3题选A。

阅读理解

I’ve loved my mother’s desk since I was just tall enough to see above the top of it as Mother sat doing letters(学问). Standing by her chair, looking at the ink bottle, pens, and white paper, I decided that the act of writing must be the most wonderful thing in the world.

Years later, during her final illness, Mother kept different things for my sister and brother. “But the desk”, she said again, “is for Elizabeth.” I never saw her anger, never saw her cry. I knew she loved me; she showed it in action. But as a young girl, I wanted heart-to-heart talks between mother and daughter. They never happened. And a gulf opened between us. I was too emotional. But she lived “on the surface”.

As years passed, I had my own family. I loved my mother and thanked her for our happy family. I wrote to her in careful words and asked her to let me know in any way she chose that she did forgive(原谅)me. I posted the letter and waited for her answer. None came. My hope turned to disappointment, then little interest and, finally, peace-it seemed that nothing happened. I couldn’t be sure that the letter had even got to Mother. I only knew that I had written in, and I could stop trying to make her into someone she was not.

Now the present of her desk told me, as she’d never been able to, that she was pleased that writing was my chosen work. I cleaned the desk carefully and found some papers inside-a photo of my father and a one-page letter, folded and refolded many times. Give me an answer, my letter asks, in any way you chose. Mother, you always chose the act that speaks louder than words.

小题1:The writer began to love her mother’s desk _______.

A.after Mother died.

B.before she became a writer.

C.when she was a child.

D.when Mother gave it to her.小题2:The passage shows that _____.

A.Mother was cold on the surface but kind in her heart to her daughter.

B.Mother was too serious about everything her daughter had done.

C.Mother cared much about her daughter in words.

D.Mother wrote to her daughter in careful words.小题3:The word gulf in the paragraph 2 means ______.

A.deep understanding between the old and the young.

B.different ideas between the mother and the daughter.

C.free talks between mother and daughter.

D.part of the sea going far in land.小题4:What did mother do with her daughter’s letter asking for forgiveness?

A.She had never received the letter.

B.For years, she often talked about the letter.

C.She didn’t forgive her daughter at all in all her life.

D.She read the letter again and again till she died.小题5:What’s the best title of the passage?

A.My Letter to Mother.

B.Mother and Children.

C.My Mother’s Desk.

D.Talks between Mother and Me.

单项选择题