Weddings in the United States vary as much as the people do. There are church weddings with a great deal of fanfare(仪式上的短曲); there are weddings on mountain tops with guests barefooted; there have been weddings on the ocean floor with oxygen tanks for the guests. But many weddings, no matter where or how they are performed, include certain traditional customs.

    Before a couple is married, they become engaged. And then invitations are sent to those who live nearby, their close friends and their relatives who live far away. When everything is ready, then comes the most exciting moment.

    The wedding itself usually lasts between 30 and 40 minutes. The wedding party enters the church while the wedding march is played. The bride carrying a bouquet enters last with her father who will “give her away”. The groom enters the church from a side door. When the wedding party is gathered by the altar, the bride and groom exchange vows(誓言). It is traditional to use the words “to have and to hold from this day forward, for better, for worse, for richer, for poorer, in sickness and in health, to love and to cherish, till death do us part.” Following the vows, the couple exchange rings. Wearing the wedding rings on the fourth finger of the left hand is an old custom.

    After the ceremony, there is often a party, called a “reception” which gives the wedding guests an opportunity to congratulate the new couple.

    The car in which the couple leaves the church is decorated with balloons. The words “Just Married” are painted on the trunk or back window. And then the couple go in their honeymoon.

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With around 100 students scheduled to be in that 9:00 am Monday morning lecture, it is no surprise that almost 20 people actually make it to the class and only 10 of them are still awake after the first 15 minutes; it is not even a surprise that most of them are still in their pajama's(睡衣). Obviously, students are terrible at adjusting their sleep cycles to their daily schedule.

    All human beings possess a body clock. Along with other alerting systems, this governs the sleep/wake cycle and is therefore one of the main processes which govern sleep behaviour. Typically, the preferred sleep/wake cycle is delayed in adolescents, which leads to many students not feeling sleepy until much later in the evenings. This typical sleep pattern is usually referred to as the “night owl” schedule of sleep.

This is opposed to the “early bird” schedule, and is a kind of disorder where the individual tends to stay up much past midnight. Such a person has great difficulty in waking up in the mornings. Research suggests that night owls feel most alert and function best in the evenings and at night. Research findings have shown that about 20 percent of people can be classified as “night owls” and only 10 percent can be classified as “early birds” —— the other 70 percent are in the middle. Although this is clearly not true for all students, for the ones who are true night owls, this gives them an excellent excuse for missing their lectures which unfortunately fall before midday.

    Long bus rides are like television shows.They have a beginning，a middle，and an end with commercials(广告) thrown in every three or four minutes.The commercials are unavoidable.They happen whether you want them or not.Every couple of minutes a billboard glides by outside the bus window.“Buy Super Clean Toothpaste.” “Drink Good Wet Root Beer.” “Fill up with Pacific Gas.” Only if you sleep，which is equal to turning the television set off，are you spared the unending cry of “You Need It！Buy It Now！”

    The beginning of the ride is comfortable and somewhat exciting，even if you've traveled that way before.Usually some things have changed—new houses，new buildings，sometimes even a new road.The bus driver has a style of driving and it's fun to try to figure it out the first hour or so.If the driver is particularly reckless (鲁莽的) or daring，the ride can be as thrilling as a suspense story.Will the driver pass the truck in time？Will the driver move into the right or the left hand lane？After a while，of course，the excitement dies down.Sleeping for a while helps pass the middle hours of the ride.Food always makes bus rides more interesting.But you've got to be careful of what kind of food you eat.Too much salty food can make you very thirsty between stops.

    The end of the ride is somewhat like the beginning.You know it will soon be over and there's a kind of expectation and excitement in that.The seat，of course，has become harder as the hours have passed.By now you've sat with your legs crossed，with your hands in your lap，with your hands on the armrest or even with your hands crossed behind your head.The end comes just at the right time.There are just no more ways to sit.

    In the 1960s, while studying the volcanic history of Yellowstone National Park, Bob Christiansen became puzzled about something that, oddly, had not troubled anyone before: he couldn't find the park's volcano. It had been known for a long time that Yellowstone was volcanic in nature—that's what accounted for all its hot springs and other steamy features. But Christiansen couldn't find the Yellowstone volcano anywhere.

    Most of us, when we talk about volcanoes, think of the classic cone (圆锥体) shapes of a Fuji or Kilimanjaro, which are created when erupting magma (岩浆) piles up. These can form remarkably quickly. In 1943, a Mexican farmer was surprised to see smoke rising from a small part of his land. In one week he was the confused owner of a cone five hundred feet high. Within two years it had topped out at almost fourteen hundred feet and was more than half a mile across. Altogether there are some ten thousand of these volcanoes on Earth, all but a few hundred of them extinct. There is, however, a second les known type of volcano that doesn't involve mountain building. These are volcanoes so explosive that they burst open in a single big crack, leaving behind a vast hole, the caldera. Yellowstone obviously was of this second type, but Christiansen couldn't find the caldera anywhere.

    Just at this time NASA decided to test some new high-altitude cameras by taking photographs of Yellowstone. A thoughtful official passed on some of the copies to the park authorities on the assumption that they might make a nice blow-up for one of the visitors' centers. As soon as Christiansen saw the photos, he realized why he had failed to spot the caldera; almost the whole park-2.2 million acres—was caldera. The explosion had left a hole more than forty miles across—much too huge to be seen from anywhere at ground level. At some time in the past Yellowstone must have blown up with a violence far beyond the scale of anything known to humans.

    We tend to think of our dreams as being uniquely personal­nighttime stories built from our own experiences that help us process our day-to-day lives. While dreams can give us a look into our personal selves, scientists have collected data that suggests dreams make their way into our cultural fabric(结构), showing themselves in ways that shape beliefs and expose collective anxieties.

    Roger Ivar Lohmann of Trent University conducted research with the Asabano people of the rainforest of Papua New Guinea, a unique group who didn't have outside contact until 1963. His studies looked at how dreams shape their beliefs and actions.

    According to Lohmann's research, dreams act as a sort of motivator or determinant of Asabano behavior. For instance, a dream may affect the way a person hunts or goes about treating medical conditions. The way dreams determine behavior is due to what Lohmann calls the "night residue" effect. This means that specific memories of dreams can affect the way a person acts when awake and inform their belief system.

    Dreams also seem to have an effect on the way many define themselves within their own cultures, and how sometimes reaching a distinct definition can cause anxiety.

    Matt Newsom of Washington State University spoke with college students in Berlin, and found many students had dreams surrounding conflicting views about their own identities(身份) in relation to what they saw as a return of German nationalism, which is a sensitive subject especially when we think of German identity as it's defined even many years after World War Ⅱ.

    Many students had dreams that centered around anxieties like "Where do I belong?" Many students never talked with one another about identity struggles in their dreams, yet many reported having such dreams. Newsom noted that dreams can be helpful "for identifying (识别) unspoken social and historical anxieties present in a given society."

    All of this research suggests that dreams can do more than help explain the thought of a person; we can learn about entire cultures and collective attitudes as well.