Sometimes, you just can't help it. Maybe you're watching a sad movie, or thinking about the friend who moved away. Next thing you know, your eyes are watering, and you havetears running down your cheeks. Why do peoplecry when they are emotional? What are tears? Scientists are working hard to find the answers to these questions.

    Ad Vingerhoets is a professor of psychology at Tilburg University, in the Netherlands. He is one ofthe few scientists in the world who have studied crying. According to Vingerhoets, there are three types of tears. Basal tearsare the first type. Theylubricate(润滑) the eyes andact as a protective barrier between the eye and the rest of the World. Next arereflex tears. They wash youreyes clean when something gets in them. Finally, there are emotional tears. “These are released in response to emotional states, ”explains Vingerhoets. “Especially when we feel helpless.”

    Scientists believe that crying has something to do with how humans developed and learned to depend on each other.“Humans are very complex social creatures,”says Lauren Bylsma, a professor at the University of Pittsburgh, in Pennsylvania.“It seems that tears serve to arouse help and support from others," She says. “Another reason we weep is that humans have the longest developmental period of almost any animal. It takes along time to grow up. ”

    Vingerhoets agrees. “I think that the reason why humans shed tears(流眼泪) has somethingto do with our childhood,”he says. “That's the time when we are stir dependent on adults for love and protection and care. The major advantage of emotional tears is that you can target them at a specific person.”Vingerhoets says this ability to target someone could have come in hand in prehistorictimes, when humans were living among dangerous animals. Crying couldattract predators(捕食者). Tears were asafer way to get attention. In this case, it is better to use a silent signal to ask for help,”he says.

    Vingerhoets and Bylsma do frequent studies to better understand why humans cry. According to Byhma, there is still much more to discover. “It's surprising,”she says,“how much we still don't know.”

    If you are studying at school, do be a polite and clever student! There is no excuse for not doing your assignments. If you can't come to school, you should call your teacher or your classmate ask about homework. It is your responsibility to find out what homework you have missed. It is not the teacher's job to remind you of the missed assignments.

    You must not be absent on a test day. If you are seriously ill, call and let the teacher know you will not be there for the test. If your teacher allows a make-up test, you should take the test, again within one or two days after you return to class. Serious illness is the only reason for missing a test.

    Be on time! It is impolite to be late. Also, it bothers other students. If you must come in late, be sure to do it quietly. Have your books and papers out of your bag before you come into the classroom. Then go to your seat and sit down quietly. In the USA, it is not necessary to knock before you enter the classroom. Most teachers will give you a low grade if you are often late.

    In America, you should call your teacher by his or her last name instead of “teacher”. Also you should use Mr, Miss, Ms or Mrs before the last name (such as Mrs Smith or Mr Jones). The teacher will tell you the title that he or she likes. It is impolite in the USA to eat, drink or chew gum during class. Don't do these until the break. Also, removing your shoes in the classroom is not polite.

    We've all experienced that feeling that comes when your phone makes a sound to tell you that its battery level is low. It often comes at the worst times – when you're out on a trip and don't have a charger, or when you're expecting an important phone call.

    Indeed, this feeling is so common that South Korean electronics manufacturer LG has given it a name: low battery anxiety.

    According to a survey of 2,000 US adults conducted by the company last year, 90 percent of respondents said that they panic if their battery level reaches 20 percent or lower.

    And last month, UK telecommunications service provider 02 found that around 15.5 million Britons live in “constant fear” of their mobile phones running out of power, according to a survey by the company.

    “The problem is not about being unable to make calls, but is rooted in the fact that smartphones are now where we store digital memories,” noted the Daily Mail.

    However, battery worries don't just affect smartphone lovers. Many owners of electric vehicles also suffer from so-called “range anxiety”. This refers to the concern that the vehicle may not make it to its destination before the power runs out.

    Meanwhile, it isn't just low power that people worry about. A study carried out by South Korea's Sungkyunkwan University and China's City University of Hong Kong found that many of us also worry about not having constant access to our phone.

    This condition is known as nomophobia, short for “no mobile phone phobia（恐惧症）”. Symptoms include feeling uncomfortable when access to one's phone isn't possible, being unable to turn off your phone, and constantly topping up the battery to make sure it never dies.

    So, why do so many people treat their smartphone with such importance? The underlying reason may be that they keep us connected to the people around us, and if we're unable to use our phone, we feel like we're cut off from our social life.

    With products with bigger batteries being released all the time though - such as Xiaomi's Mi Max smartphone range or Tesla's Model S cars – battery anxiety may hopefully soon be a thing of the past.

    Parkside

    Pick Your Own

    Fancy some fresh fruit and vegetables? At Parkside Farm we grow a wide variety of delicious summer fruits and high-quality vegetables for you to come and pick your own. Why not pay us a visit?

     About us

    Our family has been farming at Parkside Farm since 1938. Although we no longer keep fields of wheat and other crops. We started growing strawberries for Pick Your Own back in 1979. Since then, we have made the Pick Your Own area larger and we now grow about 20 different crops.

     Opening times

    The season starts in late June, but opening hours are variable the first week. Please ring our message line to check. From July onwards, we are open Tuesdays to Saturdays from 9 am to 5:30 pm (last entry 5 pm). Opening hours are variable on Sundays. Mondays CLOSED.

     Crop calendar

    Some crops may be in limited supply at certain times, so always ring the message line for daily updates before setting out.

    Strawberries: early June to mid-October                Blackcurrants:     early July to mid-August

    Raspberries: mid-June to mid-August                   Redcurrants: mid-July to mid-August

    Blackberries: mid-July to mid-October                  Plums: mid-July to early September

    Prices

    There is a minimum charge of ￡3 for each adult or child who enters the Pick Your Own area. This means that every person has to spend at least ￡3 on Pick-Your-Own fruits or they will charged this amount when they leave.

    Strawberries: ￡4.49/kg         Blackcurrants: ￡4.79/kg     Raspberries: ￡6.39/kg

    Redcurrants: ￡4.79/kg          Blackberries: ￡5.39/kg     Plums: ￡ 2.99/kg

    Find us

    Parkside Farm is in the Enfield of London, north of the city centre.

    For more information , please call our message line on 020 8367 2035 or check our website: www.parksidefarmpyo.co.uk.

    Ivy Granstrom

    Ivy Granstrom was born with impaired vision(弱视) and got a serious back injury at the age of 60 during a car accident. She participated in cold English Bay swimming events for 76 years and was therefore sometimes known as the Queen of the Polar Bear Swims.

    Gerry Hewson

    Gerry Hewson was a member of Australian Men's National Wheelchair Basketball Team. He won a gold medal in the 1996 Summer Paralympics. He coached for the West Sydney Razorbacks from 2004 to 2006.He was named as a lifetime member in recognition of the efforts he made for the promotion of wheelchair basketball. Discussing the appeal of wheelchair basketball, he commented that,“There is a coating at the edge of the rim(轮辋) that actually lights up like a spark(火花), and it stays for about two to three seconds. That is quite exciting and great fun.”

    April Holmes

    April Holmes lost her left leg below the knee because of a train accident in 2001. Remembering it she said, “I had a life-changing accident in January, 2001. And fortunately I have been able to get back to doing what I love, and that's track and field.” Through hard work, she made records in the 100, 200, and 400 meter events. To live her life to its full potential, she has set up a non-profit(非营利的) organization, the April Holmes Foundation, to help people with learning or physical disabilities while being a role model for them.

    Shauna Maria Whyte

    Shauna Maria Whyte was born in Canada in 1967. She has won many prizes in cross-country skiing competitions since 1975. In 1991, during a horseback riding competition, Shauna broke her back. She did not surrender to this change in her life, and she started using a sit sled(雪橇).