C

    Measles(麻疹), which once killed 450 children each year and disabled even more, was nearly wiped out in the United States 14 years ago by the universal use of the MMR vaccine(疫苗). But the disease is making a comeback, caused by a growing anti-vaccine movement and misinformation that is spreading quickly. Already this year, 115 measles cases have been reported in the USA, compared with 189 for all of last year.

    The numbers might sound small, but they are the leading edge of a dangerous trend. When vaccination rates are very high, as they still are in the nation as a whole, everyone is protected. This is called “herd immunity”, which protects the people who get hurt easily, including those who can't be vaccinated for medical reasons, babies too young to get vaccinated and people on whom the vaccine doesn't work.

    But herd immunity works only when nearly the whole herd joins in. When some refuse vaccination and seek a free ride, immunity breaks down and everyone is in even bigger danger.

    That's exactly what is happening in small neighborhoods around the country from Orange County, California, where 22 measles cases were reported this month, to Brooklyn, N.Y., where a 17-year-old caused an outbreak last year.

    The resistance to vaccine has continued for decades, and it is driven by a real but very small risk. Those who refuse to take that risk selfishly make others suffer.

    Making things worse are state laws that make it too easy to opt out(决定不参加) of what are supposed to be required vaccines for all children entering kindergarten. Seventeen states allow parents to get an exemption（豁免), sometimes just by signing a paper saying they personally object to a vaccine.

    Now, several states are moving to tighten laws by adding new regulations for opting out. But no one does enough to limit exemptions.

    Parents ought to be able to opt out only for limited medical or religious reasons. But personal opinions? Not good enough. Everyone enjoys the life-saving benefits vaccines provide, but they'll exist only as long as everyone shares in the risks.

    In the traffic lights,red means "stop",green means "go",and yellow means "hurry": Why those colors, though? Why not blue,purple,and brown?The following are transponded from others WeChat.

●Red is an inherited symbol from railroads

    Red symbolizes danger in many cultures,which makes sense,considering it has the longest wavelength of any color,meaning you can see it from a greater distance than other colors.Red has meant "stop" since long before cars existed,with railway signals use of red dating bake to the days when mechanical arms lifted and lowered to indicate whether the rail ahead was clear.So that one's simple.

●Green meant "caution" at first

    Green's role in lights has actually changed dramatically over time.Its wavelength is next to (and shorter than) yellow's,meaning it's still easier to see than any color other than red and yellow.Back in the early days of railway lights,green originally meant "caution",while the "all-clear" light was,well,clear or white.Trains,of,course,take an unlimitedly long time to stop,and legend has it that several disastrous collisions happened after an engineer mistook stars in the night horizon for an all-clear.Thus,green became "go",and for a long time,railways used only green and red to signal trains.

●Yellow means "caution" because it's almost as easy to see as red

    From the earliest days of motoring up until the mid-1900s,not all stop signs were red-many were yellow, because at night it was all but impossible to see a red stop sign in a poorly lit area.The yellow stop-sign craze began in Detroit in 1915,a city that five years later installed its first electric traffic signal,which happened to include the very first amber traffic light,at the corner of Michigan and Woodward Aves.

    Once a group of 17-year-old schoolboys decided to break the world basketball marathon record ( 马拉松记录). They wanted to play for ninety hours and add six hours to the record. Each team had nine players, with five at a time. The boys decided each person would play 21.5 hours and then rest for 2 hours. Then it started between both of the sides at 6 o'clock in the evening.

    The first night was very hard for the players. When it was their turn to rest, they were too exited(兴奋的) to fall asleep at once. After sleeping for a short time, they had to play again.

    On the second night, they fell asleep as soon as they stopped. Some of them had trouble with their feet and hands, but the only serious problem was a psychological one. Each boy was thinking: Why am I doing this? How can I play any longer?

    After the third night, the players knew they could finish the ninety hours. The basketball on the fourth night was very slow. But in the final hours, the players got better. For the last few minutes, the players looked as fresh as when they started. How happy everyone was!

    The Oklalhoma teen's eyes were covered by two blindfolds（眼罩）. She didn't know she would meet her father, James, after 12-year separation.

    “I had actually discussed with her the night before at a restaurant and talked over the details of where we would go and how we would pull them of,” said Amanda, Rory Beth's mother.

    A video shows Amanda led her blindfolded daughter out of their car and guided her across the parking lot of Broken Arrow Lanes in Broken Arrow.

    Little did she know, her father was on the sidewalk holding a birthday cake that read, “Happy Birthday Rory Beth, Love Dad.” When the teen slowly pulled down her blindfolds, she was extremely surprised. Both the father and daughter stood silently looking at each other until James finally walked over and hugged her. James only broke their embrace to look at his daughter and hold her face. “There were definitely lots of tears from James, myself, and boys, and even a few bystanders,” said Amanda.

    James was a truck driver who spent a lot of time on the road, so Amanda ended the marriage with him when Rory Beth was a baby. “It was hard to figure out how to make it work,” Amanda said. Amanda felt Rory Beth was now old enough to understand and to ask any questions she may have, so the reunion happened.

    The birthday surprise was on June 4, and the father and daughter had seen each other again since, even celebrating Father's Day together. Amanda said her daughter and James were both delighted to be together.

    “She's already calling him 'daddy' and tells him that she loves him.” Amanda said.

    We all know what a brain is. A doctor will tell you that the brain is the organ of the body in the head. It controls our body's functions, movements, emotions and thoughts. But a brain can mean so much more.

    A brain can also simply be a smart person. If a person is called brainy, he is smart and intelligent. If a family has many children but one of them is super smart, you could say, “He's the brains in the family.” And if you are the brains behind something, you are responsible for developing or organizing something. For example, Bill Gates is the brains behind Microsoft.

    Brain trust is a group of experts who give advice. Word experts say the phrase “brain trust” became popular when Franklin D. Roosevelt first ran for president in 1932. Several professors gave him advice on social and political issues（问题）facing the U.S. These professors were called his “brain trust”.

    These ways we use the word “brain” all make sense. But other ways we use the word are not so easy to understand. For example, to understand the next brain expression, you first need to know the word “drain”. As a verb, to drain means to remove something by letting it flew away. So a brain drain may sound like a disease where the brain flows out of the ears. But, brain drain is when a country's most educated people leave their countries to live in another. The brains are, sort of, draining out of the country.

    However, if people are responsible for a great idea, you could say they brainstormed it. Here, brainstorm is not an act of weather. It is a process of thinking creatively about a complex topic. For example, business leaders may use brainstorming to create new products, and government leaders may brainstorm to solve problems.

    If people are brainwashed, it does not mean their brains are nice and clean. To brainwash means to make some accept new beliefs by using repeated pressure in a forceful or tricky way. Keep in mind that brainwash is never used in a positive way.

    A study examining the children of people evacuated(撤离) during the WWII showed the daughters of female evacuees were up to four times more likely to suffer from serious mental health conditions compared to those whose parents stayed at home.

    In the largest enquiry ever of its kind, researchers examined the health records of 3000 children of Finnish people evacuated to Sweden during the 1941-1945 conflict with Soviet Russia. The evacuees, many of whom were at a pre-school age, were placed with foster families in Sweden and were forced to learn Swedish, later returning to Finland. The study found that the female children of these girls had an increased risk of being hospitalized for conditions such as depression. However, this was not the case with children of boys evacuated during the war.

    The study could not determine why. One possibility is that the stress of the evacuees' experience affected their psychological development in ways that influenced their parenting style. Another possibility is that the evacuees' experience resulted in epigenetic changes—changed in the way genes are expressed. For example, the researchers mentioned an earlier finding that Holocaust survivors have higher levels of methyl groups bound to the FKBP5 gene and have passed his change on to their children. This higher level of methyl groups appears to change the production of cortisol, a hormone(荷尔蒙) that controls the stress response.

    "The Finnish evacuation was intended to protect children from the harm associated with the country's wars with the Soviet Union", said study co-author Dr Torsten Santavirta, from Uppsala University.

    "Our observation of the long-term psychiatric(精神病的) risk that reached into the next generation is concerning and stresses the need to weigh benefits as well as potential risks when designing policies for child protection".