这个路面标记是什么标线？（） A．禁驶区 B．网状线 C．中心圈 D．导流线

估算的结果都比实际计算的结果大．______．（判断对错）

在水平光滑细杆上穿着A、B两个刚性小球（可看作质点），用两根长度同为L的不可伸长的轻绳与C球连接，如图所示．已知A、B、C三球质量均相同，开始时三球均静止、两绳伸直且处于水平状态．现同时释放三球，求：

（l）在C球运动到最低点．A、B两球刚要相碰的瞬间，A、B两球速度的大小；

（2）在A、B相碰前的某一时刻，A、B二球速度v的大小与C球到细杆的距离h之间的关系．

阅读理解。

     When Mary Moore began her high school in 1951, her mother told her, "Be sure and take a typing course

so when this show business thing doesn't work out, you'll have something to rely on." Mary responded in

typical teenage fashion. From that moment on, "the very last thing I ever thought about doing was taking a

typing course," she recalls.

     The show business thing worked out, of course. In her career, Mary won many awards. Only recently,

when she began to write Growing Up Again, did she regret ignoring her mom, "I don't know how to use a

computer," she admits.

     Unlike her 1995 autobiography, After All, her second book is less about life as an award-winning actress

and more about living with diabetes (糖尿病): All the money from the book is intended for the Juvenile

Diabetes Research Foundation (JDRF), an organization she serves as international chairman. "I felt there

was a need for a book like this," she says. "I didn't want to lecture, but I wanted other diabetics to know that

things get better when we're self-controlled and do our part in managing the disease."

     But she hasn't always practiced what she teaches. In her book, she describes that awful day, almost 40

years ago, when she received two pieces of Iife-changing news. First, she had lost the baby she was carrying

and second, tests showed that she had diabetes. In a childlike act, she left the hospital and treated herself to a

box of doughnuts (甜甜圈). Years would pass before she realized she had to grow up-again-and take control

of her diabetes, not let it control her. Only then did she kick her three-pack-a-day cigarette habit, overcome her

addiction to alcohol, and begin to follow a balanced diet.

     Although her disease has affected her eyesight and forced her to the sidelines of the dance floor, she refuses

to fall into self-pity. "Everybody on earth can ask, 'why me?' about something or other," she insists. "It doesn't

do any good. No one is immune (免疫的) to heartache, pain, and disappointments. Sometimes we can make

things better by helping others. I've come to realize the importance of that as I've grown up this second time.

I want to speak out and be as helpful as I can be."

1. Why did Mary feel regretful?

A. She didn't achieve her ambition.

B. She didn't take care of her mother.

C. She didn't complete her high school.

D. She didn't follow her mother's advice.

2. We can know that before 1995 Mary _____.

A. had two books published

B. received many career awards

C. knew how to use a computer

D. supported the JDRF by writing

3. Mary's second book Growing Up Again is mainly about her _____.

A. living with diabetes

B. successful show business

C. service for an organization

D. remembrance of her mother

4. When Mary received the life-changing news, she _____.

A. lost control of herself

B. began a balanced diet

C. tried to get a treatment

D. behaved in an adult way

5. What can we know from the last paragraph?

A. Mary feels pity for herself.

B. Mary has recovered from her disease.

C. Mary wants to help others as much as possible.

D. Mary determines to go back to the dance floor.

硫酸和金属的反应都是置换反应。

间质性肺疾病的胸部影像学检查的哪些特点有助于基础疾病的诊断和鉴别诊断（）

A.肺容积变化

B.阴影的大小

C.阴影的分布规律

D.阴影的性质

E.阴影的形状