Humans have launched themselves into the outer space. They've landed on the moon. They've built habitable space stations that orbit the Earth. The next giant leap for mankind is to reach another planet – specifically, Mars.

    The problem is that it's no easy task. The planet is 586 times further away from the Earth than the moon, and it'll take around 180 to 220 days to reach Mars, depending on where each planet is in its orbit. Such long periods in space have suggested many potential health problems, including hormonal changes, skin conditions, and muscle and bone deterioration (损耗).

    Here's where some furry friends come in. A wide range of animals have been in space, from fruit flies and spiders to cats, and dogs. Such experiments began as far back as the late 1940s in first tests to see if living things could withstand the extreme g-force (重力) of a rocket launch.

    Mice continue to play a very important part in space experiments, mainly because the animals make excellent test subjects. They're small, which makes them inexpensive and easy to care for. In addition, their size and short life span make it possible to do the equivalent of several human years of tests in a much shorter time. Finally, because mice are mammals, they share many common characteristics with humans in terms of genetics, biology and behavior.

    Astromice have hit the headlines recently, as a team of scientists led by Betty Nusgens, professor of biology at the University of Liege in Belgium, found that the mice suffered a 15 percent thinning of their skin after 91 days aboard the International Space Station (ISS).

    This experiment was part of a wider NASA mission (任务) called the Mice Drawer System (MDS). The Italian Space Agency developed the facility, which allows six mice to be housed, monitored, and automatically fed and watered aboard the ISS, among which three survived during the mission.

    The mice have participated in 20 separate experiments, to study such effects as osteoporosis (骨质疏松症), anemia (贫血) and heart health.

    Results for the 20 experiments are coming in gradually. But it's clear that mice continue to play an important role in the ongoing quest to conquer the final frontier.

    After returning from her round trip, the angry woman stood outside the ticket office of the station. “The railway owes me 12 pounds，” she said to Harry Jenks, the young man working at the office. “You sold me a ticket for May 22nd, but there was no ship from Jersey that night. So my daughter and I had to stay in a hotel. It cost me 12 pounds.”

    Harry was worried. He remembered selling the woman a return ticket. “Come into the office, Madam，” he said politely. “I'll just check the Jersey timetable for May 22nd.”

    The woman and her little girl followed him inside. She was quite right, as Harry soon discovered. There was no sailing on May 22nd. How could he have made such a careless mistake? He shouldn't have sold her a ticket for that day. Wondering what to do, he smiled at the child. “You look sunburnt.” he said to her. “Did you have a nice holiday in Jersey？”

    “Yes,” she answered, shyly. “The beach was lovely. And I can swim too!”

    “That's fine,” said Harry. “My little girl can't swim a bit yet. Of course，she's only three ...”

    “I'm four，” the child said proudly. “I'll be four and a half.”

    Harry turned to the mother. “I remember your ticket, Madam.” he said. “But you didn't get one for your daughter, did you？”

    “Er, well ...” the woman looked at the child. “I mean .., she hasn't started school yet. She's only four.”

    “A four­-year­-old child must have a ticket, Madam. A child's return ticket from Jersey costs .., let me see ... 13.50 pounds. The law is the law, but since the mistake is mine ...”

    The woman stood up, took the child's hand and left the office.

    Good afternoon, and welcome to England. We hope that your visit here will be a pleasant one. Today, I'd like to draw your attention to a few of our laws.

    The first one is about drinking. Now, you may not buy wine in this country if you are under 18 years old, nor may your friends buy it for you.

    Secondly, noise. Enjoy yourselves, but please don't make unnecessary noise. We ask you to respect other people who may wish to be quiet.

    Thirdly, crossing the road. Be careful. The traffic moves on the left side of the road in this country. Use pedestrian crossings（人行道） and don't take any chances（冒险） when crossing the road.

    My next point is about rubbish. It isn't a law to drop rubbish in the street. When you have something to throw away, please put it in your pocket and take it home, or put it in a dustbin.

    Finally, about smoking. It is against the law to buy cigarettes if you are under 16.

    If you request any help, you should contact the police, who will be glad to help you. You can call, write, or directly go to ask any policeman.

    You know the feeling-you have left your phone at home and feel anxious, as if you have lost your connection to the world. "Nomophobia" (无手机恐惧症) affects teenagers and adults alike. You can even do an online test to see if you have it. Last week, researchers from Hong Kong warned that nomophobia is infecting everyone. Their study found that people who use their phones to store, share and access personal memories suffer most. When users were asked to describe how they felt about their phones, words such as "hurt" (neck pain was often reported) and "alone" predicted higher levels of nomophobia.

    "The findings of our study suggest that users regard smartphones as their extended selves and get attached to the devices," said Dr. Kim Ki Joon. "People experience feelings of anxiety and unpleasantness when separated from their phones." Meanwhile, an American study shows that smartphone separation can lead to an increase in heart rate and blood pressure.

    So can being without your phone really give you separation anxiety? Professor Mark Griffiths, psychologist and director of the International Gaming Research Unit at Nottingham Trent University, says it is what is on the phone that counts-the social networking that creates Fomo (fear of missing out).

    "We are talking about an internet-connected device that allows people to deal with lots of aspects of their lives," says Griffiths. "You would have to surgically remove a phone from a teenager because their whole life is rooted in this device."

    Griffiths thinks attachment theory, where we develop emotional dependency on the phone because it holds details of our lives, is a small part of nomophobia. For "screenagers", it is Fomo that creates the most separation anxiety. If they can't see what's happening on Snapchat or Instagram, they become panic-stricken about not knowing what's going on socially. "But they adapt very quickly if you take them on holiday and there's no internet," says Griffiths.

    You probably know who Marie Curie was, but you may not have heard of Rachel Carson. Of the outstanding ladies listed below, who do you think was the most important woman of the past 100 years?

    Jane Addams(1860-1935)

    Anyone who has ever been helped by a social worker has Jane Addams to thank. Addans helped the poor and worked for peace. She encouraged a sense of community(社区)by creating shelters and promoting education and services for people in need . In 1931, Addams became the first American woman to win the Nobel Peace Prize.

    Rachel Carson(1907-1964)

    If it weren't for Rachel Carson, the environmental movement might not exist today. Her popular 1962 book Silent Spring raised awareness of the dangers of pollution and the harmful effects of chemicals on humans and on the world's lakes and oceans.

    Sandra Day O'Connor(1930-present)

    When Sandra Day O'Connor finished third in her class at Stanford Law School, in 1952, she could not find work at a law firm because she was a woman. She became an Arizona state senator(参议员) and ,in 1981, the first woman to join the U.S. Supreme Court. O'Connor gave the deciding vote in many important cases during her 24 years on the top court.

    Rosa Parks(1913-2005)

    On December 1, 1955, in Montgomery, Alabama, Rasa Parks would not give up her seat on a bus to a passenger. Her simple act landed Parks in prison. But it also set off the Montgomery bus boycott. It lasted for more than a year, and kicked off the civil-rights movement. "The only tired I was, was tired of giving in," said Parks.

D

With the completion of the Human Genome（基因组）Project more than 20 years ago, and the discovery of the double helix structure of DNA enjoying its 70th birthday last year, you might assume that we know how life works. Think again!

Evolution has a 4bn-year head start on us. However, several aspects of the standard picture of how life works-the idea of the genome as a blueprint, of genes as instructions for building an organism, of proteins as precisely tailored molecular（分子）machines and more-have wildly reduced the complexity of life. 

In the excellent book How Life Works, Philip Ball explorers the new biology, revealing life to be a far richer, more delicate affair than we have understood. Ball explains that life is a system of many levels-genes, proteins, cells, tissues, and body modules-each with its own rules and principles, so there is no unique place to look for an answer to it. 

Also, How Life Works is a much more appealing title than the overused question of "What is life?". We should be less concerned with what a thing is, and rather more focused on what a thing does. Defining a living thing implies an unchangeable ideal type, but this will run counter to the Darwinian principle that living things are four-dimensional, ever changing in time as well as space.

But it's an idea that is deeply rooted within our culture. Ball points out that we rely on metaphors（比喻）to explain and explore the complexities of life, but none suffice. We are taught that cells are machines, though no machine we have invented behaves like the simplest cell; that DNA is a code or a blueprint, though it is neither; that the brain is a computer, though no computer behaves like a brain at all.

Ball is a terrific writer, pumping out books on incredibly diverse subjects. There's a wealth of well-researched information in here, and some details that are a bit chewy for the lay reader. But the book serves as an essential introduction on our never-ending quest to understand life.