鉴别胆道闭锁与胆汁粘稠最主要的检查方法是A．血清胆红素测定 B．肝酶谱测定 C．B超

著名的咏梅词《暗香》（旧时月色）和《疏影》（苔枝缀玉）是南宋词人（）的代表作。

2009年6月，美国总统奥巴马敦促国会在2010年8月就“全民医保”改革方案拿出一份法案，他也将开始雄心勃勃地宣传造势，为这份耗资庞大的医保改革“拉票”，以兑现其竞选时让美国人“病者有其医”的承诺。这表明            （   ）

A．国家是运用强制力量为全民谋福利的机构

B．现代国家阶级性已不再成为其本质属性

C．任何国家都要履行提供社会公共服务的职能

D．美国的民主是最先进的

阅读理解。

    Surveys of American teenagers find that about half of them do not get enough sleep on school nights. They

get an average of 60 to 90 minutes less than experts say they need. 

    One reason for this lack of sleep is biology. Experts say teens are biologically programmed to go to sleep

later and wake up later than other age groups. Yet many schools start classes as early as seven in the morning.

As a result, many students go to class feeling like sixteen-year-old Danny. He plays two sports, lacrosse and

football. He is an active teen-except in the morning.

    DANNY:"Getting up in the morning is pretty terrible. I'm just very out of it and tired. And then going to

school I'm out of it, and through first and second period I can barely stay awake.

    "Michael Breus is a clinical psychologist with a specialty in sleep problems. 

    Teens, he says, now commonly sleep for only 6.5 hours to 7 hours. He says sleepy teens can experience

a form of depression (压抑) that could have big effects on their general well-being. It can affect not just their

ability in the classroom but also on the sports field and on the road. 

    So what can schools do about sleepy students? The psychologist says one thing they can do is start classes

later in the morning. Eric Peterson is the head of St. George's School in the northeastern state of Rhode Island.

He wanted to see if a thirty-minute delay would make a difference. It did. 

    He says visits to the health center by tired students decreased by half. Late arrivals to first period fell by a

third. And students reported that they were less sleepy during the day. 

    Eric Peterson knows that changing start times is easier at a small, private boarding school like his. But he is

hopeful that other schools will find a way. 

    Patricia Moss, an assistant dean at St. George's School, says students were not the only ones reporting

better results. 

    PATRICIA MOSS:"I can say that generally all the teachers noticed immediately that kids were happier to be

there at eight-thirty than they were at eight."

1. According to experts like Michael Breus, how many hours of sleep should teens get every day? [ ]

A. 6.5 hours to 7 hours

B. at least 7.5 hours

C. More than 9 hours

D. Less than 7 hours

2. According to some experts, why do teens wake up later than adults?

A. Because they are lazier.

B. Because they need more sleep.

C. Because they are biologically programmed to sleep late and wake up late.

D. Because they play sports.

3. The article mentions the story of sixteen-year-old Danny to _____.

A. show how he hates getting up in the morning.

B. show how teens can be affected by a lack of sleep.

C. show how he turns from an active boy to a tired school child.

D. show how teens hate school.

4. What does Eric Peterson do about the problem of sleepy students?

A. He visits the health center.

B. He punishes late students.

C. He punishes sleepy students.

D. He starts his school time 30 minutes later.

5. Which of the followings is not true according to the article?

A. Later school time leads to fewer late arrivals.

B. Er ic Peterson’s experiment h as answered his question.

C. The writer of this article seems to support later school time.

D. Teachers of St. George’s School don’t seem to support later school time.

食管测压，当食管下括约肌，（LES）静息压降底至下列何种程度以下易导致胃食管反流（）

A.食管下括约肌（LES）静息压<20mmHg

B.食管下括约肌（LES）静息压<40mmHg

C.食管下括约肌（LES）静息压<10-30mmHg

D.食管下括约肌（LES）静息压<6mmHg

E.食管下括约肌（LES）静息压

简述土壤微生物的检测与卫生标准。