皮肌炎患者血清肌酶谱中，最具临床价值的是（）。 A.CK B.AST C.LDH D

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.

阅读材料，回答下列问题。（4分）

材料：一位多次去过西藏的朋友介绍他的旅游经验：最好的时节是每年的8月到10月；携带物品的原则是轻便、实用；防护用品最好带上墨镜、遮阳帽和防晒霜等物品；衣物中最好带上鸭绒服和防水服等；心、肺、脑和血液系统疾病患者不宜进入高原；最好携带吸氧用具等。

（1）下列甲、乙、丙、丁四幅图展示的景观，游客有可能在青藏高原看到的是_____________。

（2）针对这位朋友的下列建议，结合所学地理知识加以解释说明。

①“携带物品的原则是轻便、实用”，“最好携带吸氧用具”是因为                        。

②“防护用品最好带上墨镜、遮阳帽和防晒霜等物品”是因为                           。

③“衣物中，最好带上鸭绒服”是因为                                       。

建筑物外有围护结构的阳台，建筑面积按( )计算。

A．水平面积

B．围护结构外围水平面积一半

C．水平投影面积

D．围护结构外围水平面积

瓜类蔬菜中维生素C含量最丰富的是（ ）

A．苦瓜

B．黄瓜

C．南瓜

D．冬瓜

含理想变压器电路如图18-1-35所示，欲使负载电阻R_L。获得最大功率，则n和所获得的PL_max一值应为（）。

A．A

B．B

C．C

D．D