The old man stood there, ________.

________, creating an online store becomes fashionable. 

I will never forget the day________.

I ________, but I was too busy at that time.

________, can we have a peaceful mind and enjoy our life.

    Brian Greene, a professor of physics and mathematics at Columbia University, has created an online science education platform. He tries to "build a bridge" with things you know about, and then "bring you across that bridge to the strange place of modern physics".

    Recently I had a chance to ask Greene about wormholes (a hole which some scientists think might exist, connecting parts of space and time that are not usually connected), time travel and other mysteries of the universe. I asked him a million-dollar question: What if I went through a worm-hole and prevented my parents from meeting? "Most of us believe that the universe makes sense," Greene said. Although there are several interesting theories about time travel, he added, the laws of physics would probably prevent something so illogical from taking place. The good news is that the time paradox (悖论) is open for future physicists to solve.

    When asked how physics could become more exciting for kids, Greene said that books by Stephen Weinberg, Leonard Susskind, and other physicists," make it a great time for people who want to learn about big ideas but aren't yet ready, perhaps, to learn maths".

    When I pointed out that some students still might find physics boring, Greene said that the key is to teach them about things that are strange." The basic stuff is important," Greene said." But I think it's really important to also describe the more modern ideas, things like black holes and the Big Bang. If kids have those ideas in mind, then at least some of them will be excited to learn all the details."

    Greene has followed Albert Einstein's lead in trying to solve the mysteries of the universe. Now he wants kids to do the same. As Greene said, physics is "not just a matter of solving problems in an exam". It's about experimenting, showing an interest in strange phenomena (现象)—and having fun!

    Scientists in Argentina have created the world's first cow with two human genes that will enable it to produce human-like milk.

    Genetic engineering was used to introduce the "mothers' milk" genes into the animal before birth, according to the National Institute of Agribusiness Technology in Buenos Aires.

    As an adult, the cloned cow "will produce milk that is similar to that of humans", which will prove "a development of great importance for the nutrition of infants(婴儿)," said the institute. "The cloned cow, named Rosita ISA, is the first in the world with two human genes that contain the proteins present in human milk," said the statement.

    In April, scientists in China published details of research showing that they had created dairy cows which produced milk containing proteins found in human breast milk. But the Argentine team said the Chinese only introduced one human gene, while their research involved two, meaning the milk will more closely resemble that of humans.

    "Our goal was to raise the nutrition value of cows' milk by adding two human genes, which do good to the immune system of infants," said Adrian Mutto, from the National University of San Martin which worked with the institute.

    Cristina Kirchner, President of Argentina, said that the scientific institute made all Argentines proud. She also said that she had refused the "honour" of having the cow named after her. "They came to tell me that the name is Cristina, but what woman would like to have a cow named after her? It appeared to me to be more proper to call it Rosita."

The best ways to lose weight with walking

    Walking regularly is the easiest and least expensive form of exercise. Except for a good pair of walking shoes, no special equipment is needed. It is not necessary to join a gym. ________You can walk every day with no "rest days" in between. There is nothing to learn; people already know how to walk. There are, however, a few important things to keep in mind when walking to lose weight.

    Ways to lose weight by walking

    The first way to begin to lose weight by walking is to start walking. The initial goal should be 10,000 steps per day. Using a simple pedometer(计步器) attached to the waistband or on a belt will help you to count your daily steps. Consistency—even 10 minutes 3 times a day at first will produce the immediate results.________

    ________

    It is very important to check with your medical professional before beginning any exercise programme; especially if you are over age 65, have been required sitting or little activity for more than a year, or have been diagnosed with heart disease, pregnancy, high blood pressure, or any other medical conditions.

    How to walk to lose weight

    A good walking technique will help you achieve the physical or mental energy you need to walk consistently for the amount of time you have set for your goal. Making sure that you are using your large muscles correctly will also help to build your muscles.________

    Walking regularly can aid in muscle growth and increase the amount of calories you burn throughout the day. Eating a healthy low-fat diet will raise your metabolism(新陈代谢).________If paired the calorie burn with the correct diet, it can lead to a better form of weight loss.

A. Limit your "bad" fat intake.

B. Begin a walking programme with suitable physical qualities.

C. For example, take the stairs rather than taking the elevator.

D. It can be done anywhere and anytime, alone or with friends.

E. These two methods will help lead to a safe 1 to 2 pound weight loss per week.

F. Strong muscles burn more calories throughout the day, even when you are not walking.

G. But slowly increasing the time and the distance will encourage your weight-loss efforts.

    I was on a plane returning home to Dallas, Texas after completing my duty in Vietnam. There were no hometown parades for us veterans (退伍军人) from that 1 war and I had been warned about the unfriendliness from our countrymen at that time. 2, I was just trying to get home without incident.

    I sat, in uniform, in a window seat, 3 eye contact with my fellow passengers. No one was sitting in the seat next to me, which 4 my loneliness. A little girl, not more than 10 years old, suddenly 5 in the passage. She smiled and, without a word, 6 handed me a magazine. I accepted her 7 together with her quiet "welcome home". I turned to the window and wept. Her small 8 of caring was the first I had 9 in a long time.

    I believe in the 10 between strangers when we reach out to one another.

    Today, that young girl 11 has no memory of what happened years ago. I like to think of her as having grown up, continuing to 12 others and teaching her children to do the same. I know she might have been told to give me the "13" by her parents. It doesn't matter why she gave me the magazine. The 14 thing is that she did.

    From then on, I have followed her 15 and tried, in different ways for 16 people, to do the same for them. I know that my 17 since then are all due to that little girl. Her offer of a magazine to a tired, scared and 18 soldier has echoed throughout my 19. I have to believe that my small gestures have the same 20 on others.