一个公司获得超额利润是仅仅当它创造的价值小于为创造这些价值而发生的费用。

A lesson from the terrible drought(干旱) that hit some parts of southwestern China this year is that more anti-drought projects ______ built in the past years.

A．should be

B．should not have been

C．ought to have been

D．must be

阅读理解。

     Four people in England, back in 1953, stared at photo 51. it wasn't much-a picture showing a black X.

But three of these people won the Nobel prize for figuring out what the photo really showed-the shape of

DNA. The discovery brought fame and fortune to scientists James Watson, Francis crick, and Maurice

Wilkins. The fourth, the one who actually made the picture, was left out.

     Her name was Rosalind Franklin. "She should have been up there," says historian Mary Bowden. "if

her photo hadn't been there, the others couldn't have come up with the structure." one reason Franklin was

missing was that she had died of cancer four years before the Nobel decision. But now scholar doubt that

Franklin was not only robbed of her life by disease but robbed of credit by her competitions.

     At Cambridge university in the 1950s, Watson and Crick tried to make models by cutting up shapes of

DNA's parts and then putting them together. In the meantime, at king's college in London, Franklin and

Wilkins shone X-rays at the molecule (分子). The rays produced patterns reflecting the shape.

     But Wilkins and Franklin's relationship was a lot rockier than the celebrated teamwork of Watson and

Crick. Wilkins thought Franklin was hired to be his assistant. But the college actually employed her to take

over the DNA project.

     What she did was produce X-ray pictures that told Watson and Crick that one of their early models was

inside out. And she was not shy about saying so. That angered Watson, who attacked her in return. Mere

inspection suggested that she would not easily bend. Clearly she had to go or be put in her place.

     As Franklin's competitors, Wilkins, Watson and Crick had much to gain by cutting her out of the little

group of researchers, says historian Pnina Abir-Am. In 1962 at the Nobel prize awarding ceremony, Wilkins

thanked 13 colleagues by name before he mentioned Franklin. Watson wrote his book laughing at her. Crick

wrote in 1974 that "Franklins was only two steps away from the solution." 

     No, Franklin was the solution. "She contributed more than any other player to solving the structure of

DNA. She must be considered a co-discoverer," Abir-Am says. This was backed up by Aaron Klug, who

worked with Franklin and later won a Nobel Prize himself. Once described as the "Dark Lady of DNA",

Franklin is finally coming into the light.

1. What is the text mainly about?

A. The disagreements among DNA researchers.

B. The unfair treatment of Franklin.

C. The process of discovering DNA.

D. The race between two teams of scientists.  

2. Watson was angry with Franklin because she _____.

A. took the lead in the competition

B. Kept her results from him

C. proved some of his findings wrong

D. shared her data with other scientists

3. Why is Franklin described as "Dark Lady of DNA"?

A. She developed pictures in dark labs.

B. She discovered the black X-the shape of DNA.

C. Her name was forgotten after her death.

D. Her contribution was unknown to the public.

4. What is the writer's attitude toward Wilkins, Watson and Crick?

A. Disapproving.

B. Respectful.

C. Admiring.

D. Doubtful.

翠霞散功效与作用

世界银行发展委员会春季会议在2010年4月25日通过了发达国家向发展中国家转移投票权的改革方案，这次改革使中国在世银的投票权从目前的2．77%提高到4．42%，成为世界银行第三大股东国，仅次于美国和日本。这反映（）

A.我国积极参与一切国际组织的活动

B.我国是一个对维护世界安全负责任的大国

C.我国在国际社会中日益扮演着更重要的角色

D.我国外交政策的基本目标是维护世界和平、促进共同发展