问题 单项选择题 A1/A2型题

某技术员在进行金瓷修复体基底冠表面粗化及预氧化处理后,不慎用手触摸金属表面,使表面污染,最易导致金瓷修复体()。

A.瓷结合不良

B.不透明瓷层出现裂纹

C.出现瓷气泡

D.金属氧化膜过厚

E.PFM冠变色

答案

参考答案:A

选择题
阅读理解

阅读理解。

                                                   When milk arrived on the doorstep

     When I was a boy growing up in New Jersey in the 1960s, we had a milkman delivering milk to our

doorstep. His name was Mr. Basille. He wore a white cap and drove a white truck. As a 5-year-old boy,

I couldn't take my eyes off the coin changer fixed to his belt. He noticed this one day during a delivery

and gave me a quarter out of his coin changer.

     Of course, he delivered more than milk. There was cheese, eggs and so on. If we needed to change

our order, my mother would pen a note-"Please add a bottle of butter- milk next delivery"-and place it in

the box along with the empty bottles. And then, the buttermilk would magically (魔术般) appear.

     All of this was about more than convenience. There existed a close relationship between families and

their milkmen Mr. Basille even had a key to our house, for those times when it was so cold outside that

we put the box indoors, so that the milk wouldn't freeze. And I remember Mr. Basille from time to time

taking a break at our kitchen table, having a cup of tea and telling stories about his delivery.

     There is sadly no home milk delivery today. Big companies allowed the production of cheaper milk,

thus making it difficult for milkmen to compete (竞争). Besides, milk is for sale everywhere, and it may

just not have been practical to have a delivery service.

     Recently, an old milk box in the countryside I saw brought back my childhood memories. I took it

home and planted it on the back porch (门廊). Every so often my son's friends will ask what it is. So I

start telling stories of my boyhood, and of the milkman who brought us friendship along with his milk.

1. Mr. Basille gave the boy a quarter out of his coin changer _____.

A. to show his magical power

B. to pay for the delivery

C. to satisfy his curiosity

D. to please his mother

2. What can be inferred from the fact that the milkman had the key to the boy's house?

A. He wanted to have tea there.

B. He was a respectable person.

C. He was treated as a family member.

D. He was fully trusted by the family.

3. Why does home milk delivery no longer exist? 

A. Nobody wants to be a milkman now.

B. It has been driven out of the market.

C. Its service is getting poor.

D. It is forbidden by law.

4. Why did the author bring back home an old milk box?

A. He missed the good old days.

B. He wanted to tell interesting stories.

C. He needed it for his milk bottles.

D. He planted flowers in it.