At the beginning of this century, medical scientists made an interesting discovery; we are built not just of flesh and blood but also of time. They were  (1)  to show that we all have “a body clock”  (2)  us, which controls the  (3)  and fall of our body energies,  (4)  us different from one day one to the next.

The   (5)  of “a body clock” should not be too  (6)  since the lives of most living things are controlled  (7)   the 24 hour night-and-day cycle. We feel  (8)  and fall asleep at night and become   (9)  and energetic during the day. If the 24 hour-cycle is  (10)  , most people experience unpleasant  (11)   . For example, people who are not  (12)   to working at night can find that  (13)   of sleep causes them to  (14)  badly at work.

  (15)   the daily cycle of sleeping and  (16)  , we also have other cycles which  (17)  longer than one day. Most of us would   (18)  that we feel good on some days and not so good on  (19)   ; sometimes our ideas seem to flow and at other times, they  (20)  ​do not exist.

A new study has found the amount of antibiotics(抗生素) given to farm animals is expected to increase by two thirds over the next 15 years. Researchers are linking the growing dependence on the drugs to the increasing need for meat, milk and eggs. However, the drugs could quicken the development of antibiotic-resistant infections(感染).Such infections are already a major public, health concern in the United States.

The World Health Organization notes when people stop living in poverty, the first thing they want to do is eat better, rather than earn more money. For most people, that means their diet should contain more meat. With the rapid development of Asia, people there are eating nearly four times as much meat, milk and other milk products as they did 50 years ago.

To meet the need, farmers have put many animals into smaller space. As the animals are crowded together, the easiest way to deal with some of the problems of crowding is to give them antibiotics. It's clear that antibiotics help animals stay healthy in a crowded environment and grow faster. But bacteria can develop resistance to the drugs gradually.

Nowadays, doctors find antibiotics that once worked against the infections no longer work. The bacteria have learned ways to fight against the drugs. The heavy use of antibiotics in animals is responsible for the growth of antibiotic resistance worldwide. In the United States, at least two million people get drug-resistant infections each year and at least 23,000 die from an infection.

Europe has banned the use of antibiotics to increase animal growth. And the United States is hoping to persuade farmers to stop using antibiotics for that purpose.

●Cliffs of Moher, Ireland

Stretching for five miles along Ireland⁵s western coast, the Cliffs of Moher are a sight more than 300 million years in the making. At their highest, the cliffs soar an impressive 702 feet above the Atlantic Ocean, offering the million visitors who visit each year incredible views sure to leave hearts racing both from the beauty and the height.

●  White Cliffs of Dover,UK

These famous cliffs along England’s south-eastern coast are as rich in history as they are in beauty. They stand tall along the Strait of Dover, separating England from France and continental Europe. During World War I, the first bomb to hit the UK fell in Dover, and it served as a prominent location during WWII as well. And nowadays, the city is the best known for the beauty of its chalky white cliffs.

●Mount Thor, Canada

The name Mount Thor may inspire fear or respect — as well it should, considering this is the steepest, tallest cliff in the world. Thor reaches an astonishing 4_?101 feet above sea level, and the utter greatness of its vertical incline kept it from being successfully gone up until 1965. Today,it remains a challenging and popular place for rock climbers. ˈ

●Cliffs of Etretat,France

Located along France’s Alabaster Coast, these cliffs offer more than just steep walls. Climb to the top and you’ll have views of arched rock formations, as well as scenery that inspired the famous painter Claude Monet. At various points along the cliffs⁵ 80-mile stretch, you can spot natural sculptures that are said to resemble an elephant, among other things.

Although it was autumn, the snow was already beginning to fall in Tibet. Our legs were so heavy and cold that they felt like blocks of ice. Have you ever seen snowmen ride bicycles? Thatˈs what we looked like! Along the way children dressed in long wool coats stopped to look at us. In the late afternoon we found it was so cold that our water bottles froze. However, the lakes shone like glass in the setting sun and looked wonderful. Wang Wei rode in front of me as usual. She is very reliable and I knew I didnˈt need to encourage her. To climb the mountains was hard work but as we looked around us, we were surprised by the view. We seemed to be able to see for miles. At one point we were so high that we found ourselves cycling through clouds. Then we began going down the hills. It was great fun especially as it gradually became much warmer. In the valleys colorful butterflies flew around us and we saw many yaks and sheep eating green grass. At this point we had to change our caps, coats, gloves and trousers for T-shirts and shorts.