在抛物线y=-x2上,当y<0时,x的取值范围应为( ) A.x>0 B.x<0

题型:选择题

问题:

在抛物线y=-x2上,当y<0时,x的取值范围应为(  )

A.x>0

B.x<0

C.x≠0

D.x≥0

考点:二次函数的定义
题型:选择题

数据模型按不同应用层次分成3种类型,它们是概念数据模型、______和物理数据模型。

题型:选择题

开放自己的心灵世界,要求我们做到[ ]

①多与老师沟通

②乐于和同学沟通

③经常和父母沟通

④在课堂上经常讲话

A.②④

B.②③

C.①②③

D.①②③④

题型:选择题

患者,女性,33岁。蓄电池厂工作,已连续加班两周,突然发现腹绞痛。查体:血压140/80mmHg,呼吸金属味,腹肌微紧,脐周及下腹压痛。急救用药应选用()。

A.依地酸二钠钙

B.亚甲蓝

C.螺内酯

D.阿托品

E.硫代硫酸钠

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阅读理解

     Cut out part of a healthy person's liver and transplant it into a sick person--it sounds like a

complicated and dangerous operation , not to mention very expensive. But it is sometimes the

only possible cure for a seriously ill patient with liver disease.

     Until now British scientists have just announced a new stem cell technique, which allows them

to grow healthy liver cells outside human bodies. According to the researchers, it could be another

five to 10 years before the technique can actually be used to help patients with liver disease.

However, they say the method might one day replace liver transplants altogether. The study was

led by the University of Cambridge and the Welcome Trust Sanger Institute, a British genomics

and genetics research institute. It was published in the journal nature on October 12,2011.

     The researchers took skin cells from a patient with a mutation (变异) in a gene called

alphal-antitrypsin (a-l抗胰蛋白酶). This gene makes a protein that protects our bodies against

inflammation (炎症). People with changed or damaged alphal-antitrypsin are not able to release

the protein correctly from the liver, so the protein is trapped there and eventually leads to liver

cirrhosis (肝硬化).

     Scientists then used an advanced technique to cut away the faulty section of DNA from a stem

cell and replace it with a corrected one, according to the journal. The stem cells went on to produce

fresh and healthy liver cells with normal protein levels. Scientists put the new liver cells into mice

and found that they worked very well.

     Stem cells are the life source of all other cells in the body. They could transform medicine,

providing treatment for blindness, spinal cord injuries and other serous injuries. They could also be

used to produce new cells for damaged organs.

     David Lomas, a Cambridge biology professor who worked on the team, said: "If we can use a

patient's own skins cells to produce liver cells that we can put back into the patient, we may prevent

the future need for transplantation. "

1. what is the best title of this passage?

A. How to transplant liver for patients

B. A new way to transplant livers for patients  

C. The difficulty in curing liver patients

D. New life for liver patients

2. The first paragraph is written to _______.

A. show how difficult it is to cure liver disease  

B. tell us what a liver transplant involves    

C. introduce a potential cure for liver disease

D. show how serious liver disease can be

3.Why do some people get liver cirrhosis according to the article?

A. Because their bodies are lacking in alphal-antitrypsin.

B. Because their skin cells are not able to protect against inflammation.

C. Because the alphal-antitrypsin in their bodies is changed or damaged.

D. Because their liver releases too high a level of protein.

4. According to British scientists, liver transplant might ___________.

A. become history sooner or later

B. be replaced by a new stem cell technique in five years

C. be the only possible cure liver disease in the future

D. be prevented in the future

5. What can be inferred from the passage?

A. Stem cells can keep liver cells healthy and fresh.    

B. Equaling medicine, stem cells can cure blindness, spinal cord injuries and other serous injuries

C. Stem cells can replace the damaged organs.

D. All other cells in the body can't work well without stem cells

题型:选择题

下列关于人种的说法,错误的是[ ]

A.各人种分散在世界各地

B.各人种的差别表现在肤色、发色和面部特征上

C.种族的产生要比人类的产生晚得多

D.世界上只有三大人种

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