假设你是李华。你的美国笔友Susan要在暑假来中国桂林参加一个文化交流活动。 她想提前了解一下这座城市的相关情况，写信向你询问，请根据以下提示信息，给她回一封信。

注意： 1）词数100左右，开头和结尾已经给出，但不计入总数；

2）可适当增加细节，以使行文连贯；

3）参考词汇   象鼻山 Elephant Trunk Hill   chilli sauce

Dear Susan,

I'm glad that you are coming to Guilin for an exchange program during the summer holiday.

Yours

Li Hua

What comes first: the optimism or the good health?

    Optimism, defined as the general expectation that the future will be favorable, could provide ways to improve health, some researchers believe. But scientists remain unsure if optimism goes ahead of health improvements, or vice versa.

    A recent study suggests that most people can't help but to think optimistically. This study was conducted by Ed O'Brien, a social psychologist at the University of Michigan in Ann Arbor. The findings suggest that people have a natural tendency to think positively about their future.

    Participants were asked to create a list of imaginary personal experiences that would make them happy or unhappy over the course of the next year. They then ranked how difficult it was to plan that list and how happy they believed they would be in the future overall. The easier it was for people to think of positive future experiences, the happier they imagined they would be. However, there was no relationship between easily developing negative future experiences and expecting to be unhappy as a result.

    O'Brien concluded that people seem to discount the possibility that future negative events will make them happy overall, suggesting that optimism might come more naturally. "We're not as used to thinking about the future in terms of things that are going to go wrong." O'Brien's study is one of many to find that people are consistently optimistic about their future, predicting pleasant experiences and discounting unpleasant ones. If optimism may lead to better health and people generally tend to think optimistically, what does this mean for the connection between mental and physical health? "If we can make sure that optimism comes before healthy states, we might be able to involve and improve people's optimism," Boehm explained. However, it's difficult to determine what comes first: the optimism or the good health.

    Sadness and depression?

    Sadness is normal human emotion that everyone experiences at some time. A number of events can leave people feeling sad or unhappy, such as the loss or absence of a loved one, divorce, loss of job or income, financial trouble, issues at home, or social anxiety.

    Failing an exam, not getting a job, or other disappointing events can also trigger sadness.

    However, a person who is sad can usually find some relief from crying, venting, or talking out frustrations. This is because sadness is more likely to be linked to a specific trigger.

    Sadness usually passes with time. If it does not pass, or if the person become unable to function normally, this could be a sign of depression. If symptoms worsen or last longer than 2 weeks, the person should talk to their doctor.

    Depression is a mental disorder that affects every part of a person's feelings and perception. It affects behaviors and attitudes and can affect people of any gender or age.

    In 2015 around 16.1 million people aged 18 years or above in the U. S. had experienced at least one major depressive episode in the last year. This represented 6.7 percent of all American adults. Symptoms include feelings of discouragement, sadness, hopelessness, a lack of motivation, and a loss of interest in activities that are normally enjoyable. In severe cases, the person may think about or attempt suicide.

    The person may no longer feel like spending time with family or friends. They may stop pursuing their hobbies and feel unable to go to work or school.

    Daily habits may change unexpectedly and without reason. A person with depression may find it difficult to continue doing the things they normally enjoy.

    If these feelings of doubt last more than 2 weeks, a health-care professional may diagnose the person with major depressive disorder (MDD).

    Unlike sadness, depression can leave a person struggling to express their feelings. If the person tries to release the stress, the overpowering feelings and negative thoughts can prevent them from building themselves up again.

    Why do earthquakes happen? Scientists believe that the surface of the earth is covered by a number of moving plates. Sometimes two plates move towards and push against each other. Sometimes they stop for years but at other times they jump and an earthquake is felt. Because of the movements of these plates, California, China and Japan have a lot of earthquakes. You can see the result in San Francisco where the Pacific plate meets the North American plate. When the 1906 earthquake happened, the Pacific plate jumped 5 to 6 metres to the north.

    China is a country where many earthquakes happen. The Pacific plate is pushing China from the east and the Indian plate is pushing China from the southwest. The power of this movement created the Himalayas and Mount Qomolongma. It now causes earthquakes in China. We cannot stop earthquakes but we can do things to make sure they do not destroy whole cities. First it is not a good idea to build houses along the line where two plates meet. Second, if you think there may be an earthquake, make sure to build houses on rock rather than sand. Third, you must make the houses as strong as possible. Weak buildings will fall down in an earthquake, but strong ones may stay up.

These days, its not unusual to see middle-aged men collecting Star Wars action figures, office workers wearing Hello Kitty accessories, or celebrities like David Beckham playing with Lego bricks, it's becoming more and more common to see adult taking an interest in toys, comic books and the activities that are traditionally associated with children. This phenomenon has given rise to a new word: kidult.

What lies behind the phenomenon? One is about adults' nostalgia (怀旧)for the carefree days of childhood, and this is especially true with today's fast-paced, stressful lifestyles. Another is about a societal change in recent decades where people are starting families later. As a result, they have more time and money to spend on themselves. Some adults could only window-shop for their dream toys when they were kids, but now they can afford that radio-controlled car or high-priced doll they have always wanted.

Society traditionally disapproves of adults who refuse to put aside childhood interests, viewing the refusal as a sign of social immaturity (不成熟) and irresponsibility. Those who agree with this view sometimes claim that kidults are suffering from the pop-psychology concept known as Peter Pan Syndrome, an anomaly (异常) that people remain emotionally at the level of teenagers.

From the standpoint of kidults, though, this phenomenon is seen as nothing but harmless fun. Kidults insist that having youthful interests keeps them young, happy and creative, and their refusal to conform to society's acccptable tastes shows independent thinking. Besides, they argue that being part of the social trend of delayed adulthood is not purely a personal choice. The real causes include expensive housing, increased educational requirements for employment and poor work opportunities.

Whatever happened to the fight of carbon capture?

Debates have been going on around the subject of carbon capture. Scientists, especially engineers and geologists, have strongly criticized green groups who claimed that carbon capture and storage (CCS) schemes are costly mistakes.

The scientists insisted that such schemes are vital weapons in the battle against global heating. They also wan that failure to set up ways to trap and store carbon would make it impossible to meet the emissions target by 2050." CCS is going to be the only effective way in the short term to prevent our steel industry, cement manufacture and many other processes from continuing to pour emissions into the atmosphere," said Professor Stuart Haszeldine, of Edinburgh University. "If we are to have any hope of keeping global temperature increases down below 2 degrees Celsius, we desperately need to develop ways to capture and store carbon dioxide."

Green groups claimed CCS would not make "a meaningful contribution to 2050 climate targets". They say CCS was not a reliable way to decarbonize the energy system and that CCS has a "history of over-promising and under-delivering". Instead, they urged the construction of more renewable energy plants to be given priority.

But the claims were dismissed by engineers and geologists, "These claims are quite unfair" said Michael Stephenson, director at the British Geological Survey. "The technology behind carbon capture and storage is fully mature. It offers us a genuine solution to some of the problems we face in trying to deal with global warming."

A government spokesman for the Department of Energy and Climate Change said, "We are committed to meeting our climate change targets in a way that is affordable and provides secure energy to families and businesses. We are considering the role that CCS could play in decarbonization of the UK. But we also need to take government spending into account. CCS had better come down in cost."