The streams are about 12 to 15 feet wide and 300 feet or more long, scientists said. "What we're dealing with is wet soil, thin layers of wet soil, not standing water," said Aifred  McEwen of the University of Arizona at Tueson! the principal scientist for the Mars Reconnaissance Orbiter's high-resolution imaging experiment,

     Because liquid water is essential to life, the findings could have major implications for the possibility of Martianlife, There searchers said further exploration is needed to determine whether microscopic life exists on the planet.

    The presence of liquid water could also make life easier for astronauts visiting or living on Mars. Watercould be used for drinking and for creating oxygen and rocket fuel. NASA's goal is to send humans there inthe 2030s.

    The evidence of flowing water consistslargely of dark, narrow streaks(条痕) on the surface that tend to appear and growd uring the warmest Martian months and fade the rest of the year.

    Mars is extremely cold even in summer,and the streaks are in places where the temperature is as low as minus 10 degrees Fahrenheit. But salt can lower the freezing point of water and melt ice.

    The source of the water is a mystery. Scientists noted it could be melting ice. It could be an underground a quifer, which is rock or sand that can hold water. It is possibly water vapor from the thin Martian atmosphere, Or it may be a combination Michael Meyer, lead scientistfor NASA's Mars exploration program, said the only definitive way for now to determine whether there's life on Mars is to collect rocks and soil foranalysis on Earth - something a U.S. lander set for lift-off in 2020 will do.

    In many big cities, a lot of old people keep birds, cats, dogs and other animals in their houses. These animals are friendly to the old people and never leave them. So the old people love them and see them as their good friends or families.

    It's not difficult to keep these lovely animals at home. But you have to take them to animal hospitals to give them needles (注射), so they won't get ill or they will make people ill. Now there are lots of animal food stores here and there. People can buy good animal food for their animals there. Old people can buy animal food on the phone or on the Internet. But it's a little more expensive.

    Sometimes it's kind of dirty and dangerous to keep animals. They sometimes look dirty and smell terrible and can be dangerous. For example, an old woman in Shanghai lost her life on the street for her pet dog.

    Maybe old people in big cities have many reasons to keep these nice and clever animals. They may feel lonely when their children leave. And these pets can be their great helpers. They are their good friends and help them in many things.

    The Trans-Siberian Railway is a single train line that crosses nearly the complete length of Russia, from Moscow to Vladivostok. It covers a total of 5,772 miles, running from Europe to Asia. Unlike the longest flight in the world, which just began transporting passengers in 2018, the Trans-Siberian Railway started its business in 1916.

    Anyone who has taken this long journey, or even just part of it, will tell you that it travels at a rather slow speed, passing through some amazing, remote areas of Russia. You don't have to make the full journey without stopping. Instead, you're suggested to get off where there are attractive views, since it stops in some pretty fantastic places. But you certainly can take the full journey non-stop. If you do, the trip will take about 144 hours—six full days!

    You can book tickets with travel agencies. You can also make the booking online and tickets will be sent to your hotel or personal address. Children under 4 years old accompanied by adults can travel free, but cannot take up a seat. A child ticket needs to be bought if you want to get a seat for the child.

    There are longer railway services in the transportation world, but only one of them is a passenger line as some longer routes transport goods, not travelers. This railway may not be the fastest or the most modern, but it's clearly still an important player in the transportation world!

    Psychology has a new application in the field of medicine. Many doctors, together with their patients, are looking for alternative methods of treatment of physical problems. In large hospitals, modern therapy(疗法)seems to focus on the physical disease. Patients may feel they are treated like broken machines. Some doctors have recognized this as a problem. They are now using psychological therapy, in which the patient is working with the doctors against the disease with the help of medicine. The patient does not wait for the medicine and treatment to cure him or her, but instead the patient joins in the fight.

    The doctor knows that a disease affects a patient's body physically. The body of the patient changes because of the disease. He is not only physically affected, but also has an emotional response to the disease. Because his mind is affected, and his attitude and behavior change. The medical treatment might cure the patient's physical problems, but the patient's mind must fight the emotional ones. For example, the studies of one doctor, Carl Simonton, M.D., have shown that a typical cancer patient has predictable attitudes. She typically feels depressed, upset, and angry. Her constant depression makes her acts unfriendly toward her family, friends, doctors, and nurses. Such attitudes and behaviors prevent recovery. Therefore, a doctor's treatment must help the patient change that. Simonton's method emphasizes treatment of the "whole" patient.

    The attitude of a cancer patient receiving radiation therapy, an X-ray treatment, can become more positive. The physician who is following Simonton's psychological treatment plan suggests that the patient imagine that he or she can see the tumor(肿瘤)in the body. In the mental picture, the patient "sees" a powerful beam of radiation like a million bullets of energy. The patient imagines the beam hitting the tumor cells and causing them to shrink. For another cancer patient, Dr. Simonton asks him to imagine the medicine going from the stomach into the bloodstream and to the cancer cells. The patient imagines that the medicine is like an army fighting the diseased cells and sees the cancer cells gradually dying and his blood carrying away the dead cells. Both the medical therapy and the patient's positive attitude fight the disease.

    Doctors are not certain why this mental therapy works. However, this use of psychology does help some patients because their attitudes about themselves change. They become more confident because they use the power within their own minds to help stop the disease.

    Another application of using the mind to help cure disease is the use of suggestion therapy. At first, the doctor helps the patient to concentrate deeply. The patient thinks only about one thing. He becomes so unaware of other things around him that he is asleep, or rather in a trance(催眠状态). Then the physician makes "a suggestion" to the patient about the medical problem. The patient's mind responds to the suggestion even after the patient is no longer in the trance. In this way, the patient uses his mind to help his body respond to treatment.

    Doctors have learned that this use of psychology is helpful for both adults and children. For example, physicians have used suggestion to help adults deal with the strong pain of some disease. Furthermore, such treatment may help the patient with a chronic diseases. Suggestion has been used to change children's habits like nail­biting, thumb­sucking, and sleep­related problems.

    Many professional medical groups have accepted the medical use of psychology and that psychology has important applications in medicine.

    City: Hangzhou

    Launched: 2008

    Size: 2,965 stations/ 69,750 bikes

    Price: $32.61 deposit（押金）+ time charge

    While taking a look at this city, you may see the best bike sharing in the world. As the second on the planet by size, the Hangzhou Public Bicycle System is one of the most common and useful shares, largely because it's combined with public transportation: a single card can be used in subway, bus, taxi and bike sharing. Residents and tourists can put down a deposit of 200 Chinese Yuan （about $33）and ride for an hour for free in this scenic city. Each additional hour costs only $0.15. It was also the first new﹣generation bike﹣sharing system in China. By 2020 it's projected to have 175,000 bikes.

    City: Barcelona

    Launched: 2007

    Size: 420 stations/ 6,000 bikes

    Price: $61.93 per year

    Barcelona's Bicycling Program developed Spain's bike﹣sharing business in a big way. This program took off like wildfire on wheels, and because four times bigger in one year. It inspired different copycat programs all over the country. Today, Spain has 132 bike﹣sharing systems. The program is one of the world's most respected and popular shares. But it is only open to residents and tourists are not allowed to use it.

    City: Paris

    Launched: 2007

    Size: 1,751 stations/ 23,900 bikes

    Price: $38.52 per year/ $2.26 per day

    Paris's bike﹣sharing is the star of the world. Launched in 2007, it is the world's largest outside of China. Cheap by American standards, you can ride around Paris on a €1.7 day pass— the first half hour of each trip is free. Because this system covers the city with an average of 50 stations per square mile, it's a favourite with both locals and tourists.

WELCOME AND ARRIVAL INFORMATION

    Welcome to Harvard University Housing and thank you for choosing to live with us. To help you make a smooth transition please read the information below on panning your arrival.

    Pets

    Dogs living with you in your pet-friendly apartment must be vaccinated(接种疫苗) for rabies and licensed with the City of Cambridge every year.

    International Students

    Consider unlocking your phone prior to leaving your home county. This will enable you to use a SIM card from a company such as campus SIMS or US Mobile in your phone after you arrive. Those SIM cards may be available at the Property Management Office.

    Driving

    If you plan on bringing a moving van or truck it will not fit under the overpasses(天桥) on Soldiers Field Road and Memorial Drive. Plan your route in advance to avoid a risky and costly problem.

    Parking arrangements for trucks and vans must be made in advance as well. Visit your property page for information about parking your car.

    Furniture and Lighting

    Most HUH units have no furniture-the unit is empty except for a stove and a refrigerator. You need to bring, buy, or rent a bed, other furniture, and household items. In many HUH units, rooms do not have overhead lights, so you also may need table or floor lamps.

    If you want to stock up on groceries and some household items as soon as you arrive, please find information about "Grocery Shopping" by clicking the drop-down menu.