受到刺激后能够产生和传导兴奋的组织是（　　）

    One student took a box of chicken to class. Another carried on a cell-phone1and still another whistled loudly every time the2turned his back. Reform school? No. College.

    More and more, professors say, they are3 across rude students in their classrooms. Many of today's young scholars arrive late, leave4talk loud or take care of personal 5such as paying bills during class.

    Why are the students behaving badly?  “Because they can,” said a student of University of North Texas. “A lot of the time, the professors 6them get away with it.”

    Some educators say it is time to bring politeness back to their classrooms—and even7taking some of the blame for bad behavior. They say that8 students are by no means the majority but that one of them can ruin an entire9

    People are10when they learn that impolite behavior is becoming more and more common in11education, says Dr. Gerald Amanda, a counselor at City College of San Francisco. They12some high school students to misbehave but think those who get to 13 will behave more politely.

    Dr. Amanda believes that society in 14 has become more tolerant of rude behavior 15 that people in power, including professors, no longer 16 standards for politeness. That leads to a growing imprudence among some college17“There's a great18 of bad behavior in the world around them, and young people see it and19 disrespect,” said Dr. Amanda20that sometimes students have no idea that they are being rude.

关于旅游资源的叙述，正确的是（   ）

B

    People often think of the North Pole(北极) and the South Pole as similar frozen(冰冻的) wastelands. They are both places with very cold temperatures and few people live there. However, the North and South Poles are not much alike as people may imagine.

    The North Pole has no land, only thick ice. Temperatures seldom go above 32°F, at which water turns into ice. Most of the time, it stays below zero. In winter temperatures are usually as low as -30°F.

    Although conditions were very poor, people tried for many centuries to reach the North Pole. About 100 years ago, two men, Robert Peary and Mathew Henson, were able to get to this environment full of troubles and difficulties. They reached the North Pole on March 8th, 1909. It was really a hard trip for them.

    There are few things more dangerous than crossing the Arctic(北极圈) on foot. People who stayed there may face many problems: very cold temperatures, sudden storms, and even hunger. Most of the area is uninhabited. Few people can live in such a difficult place.

    People might think that with such low temperatures for most of the year, the ice would be thick and hard. However, this is not true in the Arctic. The movement of the ocean water under the ice may often cause many different changes on the surface. Sometimes the ice breaks into two opening lanes of water(水道) called “leads”. Anyone who falls into a lead can be frozen to death in a few minutes.