【推荐1】Our lives are ruled by time and we use time to tell us what to do. Fixed within our genes, and those of almost all life on earth, are the instructions for a biological clock. And they also affect our levels of attention, mood, physical strength, blood pressure and much more.

    1     By contrast, as dawn approaches, our bodies get themselves ready for increased activity when we wake. Few of us appreciate this internal world, however. We are drawn by an apparent freedom to sleep, work, eat, drink or travel when we want.

    2     If you are alert in the morning and go to bed early, you are a morning “lark”, but if you hate mornings and want to keep going through the night, you are a night “owl”.     3     In our first decade, we tend to wake early, but by the time we are teenagers, bedtimes and getting-up times become later and later.

This habit of getting up later continues until we are about 20 years old.     4     By the age of 55-60 we are getting up as early as we did when we were 10. This could explain why young adults really do have a problem getting up in the morning. Teenagers sleep late and lack sleep because they are going to bed late but still having to get up early in the morning to go to school.

Paul Kelly, the headmaster of Monkseaton High school, has adopted a later start to the school day and this is having a positive effect.     5    However, while young adults tend to improve their performance throughout the day, their older teachers show a decline in performance over the same period.

【推荐2】An unusual experiment suggests that painting eyes on the rear ends of cows may help protect them from large predators (食肉动物), like lions.     1    

Large predators like lions are also under pressure. One serious threat to large predators comes from farmers. They often shoot or poison lions after losing farm animals for their attacks.

    2    There are many small farms in the area, with between 6 and 100 cows. At night, farmers normally keep their animals in closed areas protected from lions.

Scientists from the University of New South Wales wondered if painting pictures of eyes on the cows’ rear ends might protect them.     3    There are many examples of animals such as butterflies or fish using fake “eyes” to protect themselves.

Working with over 2,000 cows on 14 different farms, the scientists tested their ideas in a study.     4    They painted large eyes on the rear ends of one group of cows. The second group got simple Xs. The final group got nothing.

The eyes worked very well. Of the cows with eyes painted on them, none were killed. Cows with nothing on their rear ends didn’t do so well.     5    The scientists were surprised to learn that even Xs seemed to give the cows some protection. Only 4 of them were killed.