1 . If you’ve ever had trouble getting your teen up in the morning or you’ve seen your teen fall asleep during the school day, you’re not alone. Many teens have difficulty in waking up early for school, and that’s because they sleep late at night.

The American Academy of Pediatrics’ Adolescent Sleep Working Group reviewed studies about sleep in teens. Researchers studied the harmful effects of not getting enough sleep-anything less than 8.5 to 9 hours of sleep on school nights-could have on young people. They discovered not getting enough sleep may cause poor grades at school. Not getting enough sleep has also been connected to a higher risk of car accidents in teens.

It may seem as though the way to solve the problem would be for teens to just go to sleep earlier. But researchers say that isn’t likely to work. Teens experience physical changes that make falling asleep earlier difficult. Their biological (生物的) clocks just won't allow them to fall asleep at 8 p.m., even when they’re tired.

Studies have shown that just delaying (推迟) school by 30 minutes can have a great effect on a teen's health and performance. So most researchers suggest the school start time be delayed until at least 8:30 a.m. for teenagers.

Some of the benefits could include:

·Teens may be more likely to get the necessary amount of sleep.

·The delayed start time could help teens sleep during their natural sleep.

·Teens may be less likely to depend on coffee to stay awake during the day.

·Enough sleep could help teens study better in class, which could help them do better in exams.

·Sleeping longer could reduce health problems caused by a lack of sleep in the long run.

·Getting home later in the afternoon may reduce the amount of time when some teens are home alone, and could reduce the possibility that tens will take part in unhealthy activities.

But doing that can also cause some problems.

1. What does Paragraph 1 show?

A．Many teens find school too boring.

B．Many teens fail to get enough sleep.

C．Today’s teens have many difficulties.

D．Today’s teens are too lazy to get up early.

2. What do researchers of the Adolescent Sleep Working Group find?

A．Today’s teens have poor grades at school.

B．Teens should get at least 8.5 hours of sleep daily.

C．Today’s teens are in danger because of car accidents.

D．Teens can be negatively influenced by not getting enough sleep.

3. Why can’t teens fall asleep earlier?

A．Because their homework is too much,

B．Because they love staying up late at night.

C．Because their physical changes make it hard.

D．Because they have unbalanced biological clocks.

4. What would the text most probably talk about next?

A．The disadvantages of starting school later.

B．The benefits of getting enough sleep for students.

C．The methods of helping students get enough sleep.

D．The advantages of putting off the school start time.

2 . Hundreds of years ago, Native-American tribes lived in Mexico. The Aztecs built beautiful cities. They had a calendar (历法) and a written language. However, the Spanish destroyed the Aztecs in l521. For the next 300 years, Spain ruled over Mexico. That’s why Mexicans speak Spanish.
Every September l6 the Mexican people hold a celebration in Mexico City, their country’s capital. It is their Independence Day. On that date in 1821 they told Spain they would no longer be ruled. Breaking free from Spain caused a war. When it was over, the Mexicans had their own government. They made their own laws.
Today America and Mexico are friends, but it wasn’t always that way. President James Polk wanted America to reach from the Atlantic Ocean to the Pacific Ocean. He tried to buy what is now the American southwest from Mexico. Mexico would not sell. So from l846 to 1848 Mexico and America fought a war to ascertain where their borders would be. When the war ended, Mexico had lost a lot of land. Now the Rio Grande River forms the border between the two nations. America is on the north side of the river. Mexico is on the south side.
Mexico has mountains and a hot, dry climate. Crops can grow on only a small part of the land. Still, Mexicans grow much of the coffee, oranges, and sugar used in the US. Mexicans have influenced building styles in southwestern US and added words such as patio and canton to American English. Americans also enjoy eating many Mexican foods like burritos, tacos, tortillas, and tamales.
1. According to the passage, what happened second on historical timeline?

A．Mexicans declared their independence from Spain.

B．The Spanish ruled Mexico.

C．The Aztecs lived in Mexico.

D．Americans fought a war with Mexico.

2. The passage says that President Polk wanted ________.

A．the US to expand its borders to the Pacific Ocean

B．Mexico to change its Independence Day to July 4th

C．Mexico to become one of the states of the Union

D．Americans to adopt the Mexican language

3. Another word for the underlined word “ascertain” is ________.

A．inspect	B．cover
C．change	D．determine

4. Mexicans have the following influences on America EXCEPT ________.

A．building styles	B．vocabulary
C．clothes	D．food

5. Before the Aztecs were conquered(征服), these Native Americans probably ________.

A．didn’t speak Spanish

B．couldn’t read or write any language

C．didn’t have tools

D．didn’t understand the concept of time