People born in the winter are more likely to suffer mental health disorders, according to a recent study carried out by researchers at Vanderbilt University in Tennessee.

Researchers raised baby mice from birth to weaning（断奶） in either “summer” light cycles of 16 hours of light and eight hours of dark or “winter” cycles of eight hours of light and 16 hours of dark. A third group experienced 12 hours of light and 12 hours of dark a day,

Then half the winter mice stayed in a winter cycle, while half switched to a summer schedule. The summer mice were similarly split. The mice raised in equal periods of light and dark were split into three groups, one of which stayed on the 12-hour schedule, one of which joined the winter group, and one of which joined the summer subset.

After 28 days, it turns out the summer-born mice behaved the same whether they stayed on the summer cycle or switched to winter. But among the winter-born mice, those stayed in winter kept their previous schedule, while those that switched to summer stayed active for an extra hour and a half, which indicates that mice born and weaned in a winter light cycle showed dramatic disruptions in their biological clocks.

The finding is the first of its kind in mammals, and it could explain why people born in the winter are at higher risk for mental health disorders including bipolar depression, schizophrenia and seasonal affective disorder.

“We know that the biological clock regulates mood in humans,” said study researcher McMahon. “If an imprinting mechanism（运行机制）similar to the one that we found in mice operates in humans, then it could not only have an effect on a number of behavioral disorders, but also have a more general effect on personality.”

43. How many groups of mice are there finally in all in the experiment?

A. four　　　　 　　　　 B. five　　　　　 　　　 C. six　　　　　 　　 D. seven

44. What's the main idea of the text?

　　 A. The biological clock regulates mood in humans.

B. people born in the winter are at higher risk for physical health disorders.

C. Being born in the winter has a negative effect on people's mental health.

D. The length of light will influence the behavior of the mice.

45. The underlined word "split" can be replaced by 　　　　 ? （Line 2, Paragraph3）

　　 A. divided　 　　　　　　　 B. torn　 　　　　　　　　 C. hit　　 D. ended

46. Which group of mice has changed their behavior after the experiment?

　　 A. The group born in the winter and staying in the winter.

B. The group born in the winter and switching to the summer.

　　 C. The group born in the summer and staying in the summer.

D. The group born in the summer and switching to the winter.

47. Who is the appropriate reader of the passage?

A. a job hunter　　　　　 　　　　　　　　　　　　　　 B. a student in the university

C. a newly-married couple　　　　　　 　　　　 D. an experienced dentist

Benjamin Franklin was born on January 17,1706 in Boston，America. In his life he built a successful printing and publishing business in Philadelphia；he conducted scientific studies of electricity and made several important discoveries；he was a diplomat (外交官) and statesman；he helped establish Pennsylvania’s first university and America’s first city hospital；he also organized the country’s first subscription library (收费图书馆)．
Franklin was also unequaled in America as an inventor until Thomas Edison. Ben had poor eyesight  and needed glasses to read. He got tired of always taking them off and putting them back on，so he decided to figure out a way to make his glasses let him see both near and far. He had two pairs of glasses cut in half and put half of them together. Today，we call them bifocals (双光眼镜)．Another invention of his，an iron stove，allowed people to warm their homes.
He loved to learn about new things. He also thought it was important to make life better with the things that he invented. Electricity was one of the things he experimented with when he retired from his business. Ben discovered that lightning (闪电) and electricity were the same thing. The lightning rod was an important invention that we still use today to protect buildings and ships from lightning damage.
Franklin preferred to have his inventions used freely for the comfort and convenience of everyone. Thomas Jefferson，the third president of America，called Benjamin Franklin “the greatest man of the age and country in which he lived”．To Benjamin Franklin there was no greater purpose in life than to “live usefully”．
【小题1】Benjamin Franklin was NOT a________.

A．diplomat	B．scientist
C．businessman	D．president

【小题2】The underlined word “unequaled” in Paragraph 2 means________.

A．better than any other	B．worse than any other
C．the same as others	D．confident as others

【小题3】Which of the following is NOT Benjamin’s invention?

A．Bifocals.	B．The iron stove.
C．Printing.	D．The lightning rod.

【小题4】What was Benjamin Franklin’s purpose in life?

A．To live comfortably every day.

B．To be useful to others.

C．To be a famous person in the world.

D．To earn a lot by inventing things.

Benjamin Franklin was born on January 17,1706 in Boston，America. In his life he built a successful printing and publishing business in Philadelphia；he conducted scientific studies of electricity and made several important discoveries；he was a diplomat (外交官) and statesman；he helped establish Pennsylvania’s first university and America’s first city hospital；he also organized the country’s first subscription library (收费图书馆)．

Franklin was also unequaled in America as an inventor until Thomas Edison. Ben had poor eyesight  and needed glasses to read. He got tired of always taking them off and putting them back on，so he decided to figure out a way to make his glasses let him see both near and far. He had two pairs of glasses cut in half and put half of them together. Today，we call them bifocals (双光眼镜)．Another invention of his，an iron stove，allowed people to warm their homes.

He loved to learn about new things. He also thought it was important to make life better with the things that he invented. Electricity was one of the things he experimented with when he retired from his business. Ben discovered that lightning (闪电) and electricity were the same thing. The lightning rod was an important invention that we still use today to protect buildings and ships from lightning damage.

Franklin preferred to have his inventions used freely for the comfort and convenience of everyone. Thomas Jefferson，the third president of America，called Benjamin Franklin “the greatest man of the age and country in which he lived”．To Benjamin Franklin there was no greater purpose in life than to “live usefully”．

1.Benjamin Franklin was NOT a________.

A．diplomat                              B．scientist

C．businessman                           D．president

2.The underlined word “unequaled” in Paragraph 2 means________.

A．better than any other                    B．worse than any other

C．the same as others                      D．confident as others

3.Which of the following is NOT Benjamin’s invention?

A．Bifocals.                              B．The iron stove.

C．Printing.                              D．The lightning rod.

4.What was Benjamin Franklin’s purpose in life?

A．To live comfortably every day.

B．To be useful to others.

C．To be a famous person in the world.

D．To earn a lot by inventing things.