13．Real Solutions (解决方法) to Problems
Thirty engineers were working as a team in a company. They were young and eager to learn. The management decided to teach them about finding real solutions to problems.
One day, the team was called for a (1)       in a hall. They were quite surprised and all reached the hall holding various (2)      . As they entered, they found a box placed in the center, full of flat balloons.
The manager asked everyone to pick a balloon and blow it up. Then they were asked to write their names on their respective (各自的) balloons (3)       so that the balloons wouldn't blow out. All tried, but not everyone was (4)      . Five balloons blew out due to pressure (压力).
Those who failed to mark their names on the balloons were (5)       out of the game. As a result, 25 engineers came to the next level. All the balloons carrying their names were (6)       and then put into a room, here and there.
The engineers were told to pick the balloon with his or her name on. All the 25 engineers began to search for the respective balloons in a rush. It was almost 15 minutes but no one was able to (7)       the right one. The second level of the game was over.
Then came the final level. The engineers were asked to pick any balloon and give it to person named on the balloon. Within a couple of minutes, all balloons (8)       the hands of the respective engineers.
The manager announced this was the real solution to the problem. Many times in our life, sharing and helping others give us real solutions to problems.

14． Roger: Hi, there! It was my 15th birthday last Saturday. Some of my friends and Alan. my cousin, came to celebrate it. Everyone brought me a gift, we played games, sang songs and had a big birthday cake. It was really a wonderful day! Did you do anything special last week?

Jessica: Yes, My class were on a school field trip last week. First, We went to the University of North Carolina to learn about the history of its basketball team. Many basketball stars were students there. Then we visited a museum. We learned about how the plane was invented and took many pictures there.

Sara: Well, I was lucky enough to go to a conference (会议) on charity (慈善) last Wednesday. I was so excited to meet a lot of kind people there. One of them was a boy named Richard. He spoke at the conference about the charity work that he had done in the past few years.

Martin: It was a different week than usual, Last Thursday, my school band (乐队) went to Atlanta to perform in a competition. I played the violin and we won a prize! On Friday we went to the Georgia Aquarium and got to see different kinds of sea life from over the world. It was really cool!

15．A Beautiful Moment
When I was in high school. I worked part-time helping Dad sell fruits and vegetables in the market. One day, as I was preparing the fruits, a little boy walked by with his mom and sister. He was about eight years old, and the girl, five or six. They were looking the fruits in front of me. I heard the kids say to their mom in French, "They're good!" I knew it was French, because I can speak and understand it.
Then I noticed how the mom was picking the fruits. At first I thought she was really looking at the fruits because she was facing them. But then I noticed how much she had to feel and smell each one as she picked them out. And she often asked her son if it looked okay, but looked way above where his face was. Putting what I saw together, I was sure she was blind.
Both of the kids continued to help their mom pick out the fruits. The son made sure the fruits were not obviously bad, and the daughter handed them to her mom. The woman then felt each one and smiled, and the daughter would put them into their basket. The kids were smiling while helping their mom pick the fruits out.
Their smiles and gentle manner moved me in a way that I had never seen before. It was so beautiful to see such young kids so willingly help. Most kids that age would be picking out candies or toys in a store for themselves, instead of helping their mom pick out fruits as the two kids did.
It was great to witness the moment, but not so great because I didn't tell the mom how beautiful her children were in their language. this is what I regret to this day.

16． Some primary schoolchildren have been raised in homes with more green space around. They are likely to come with larger volumes of white and grey matter in certain areas of the brain. These differences are associated (关联) with beneficial effects on cognitive function (认知功能). This is the main conclusion of a study led by the Barcelona Institute for Global Health.
The study was performed among 253 schoolchildren in Spain. Lifelong exposure (接触) to green space in the living places was recorded — using the information on the children's addresses from birth up through to the time of the study. Brain structure was studied using 3D magnetic resonance imaging (MRI). Working memory and inattentiveness (注意力不集中) were graded with computers.
"This is the first study that shows the association between long－term exposure to green space and brain structure." Says Dr. Payam Dadvand, the leading researcher of the study. "Our findings suggest that exposure to green space early in life could result in beneficial structural changes in the brain."
The findings show that long-term exposure to greenness is positively associated with white and grey matter volumes in several parts of the brain. Some of them are related to higher scores on cognitive tests. Moreover, larger volumes of white and grey matter in those parts might lead to better working memory and less inattentiveness.
Exposure to nature has been thought to be necessary for brain development in children. Another study of 2, 593 children shows that children in school with more green space have a greater increase in working memory and a greater decrease in inattentiveness.
Humans are believed to be tied to nature. Playing in greener areas offers children opportunities to search and learn. Accordingly, green space is thought to prompt important exercises in discovery, creativity and risk taking. These exercises in turn positively influence brain development.
Dr. Dadvand's study suggests how such structural changes could bring about the beneficial effects of green spaces on cognitive development. It also adds to the proof that suggests the lasting effects of early life exposure to greenness on our health and the benefits of increasing greenness in cities.
Further studies are needed to prove the findings in other populations, settings and climates. And researchers need to examine differences according to the nature and quality of green space.

17． We often reach a point in our life when we should be ready for change that will help us unlock our self-improvement power. However, there's always something staring at us right under our nose but we don't see it. The only time we think of unlocking our self-improvement power is when everything gets worst.
When do we realize that we need to change diets? When none of our shirts and jeans would fit us. When do we stop eating candies and chocolates? When all of our teeth have fallen off. When do we realize that we need to stop smoking? When our lungs have gone bad. We see the warning signs and signals when things get rough and difficult.
The only time most of us ever learn about unlocking our self-improvement power is when the whole world is falling apart. We think and feel this way because it is not easy to change, but change becomes more painful when we ignore (忽视) it.
Change will happen, like it or hate it. At one point or another. we are all going to finally unlock our self-improvement power not because the world says so, but because we realize it's for our own good.
Happy people don't just accept change; they embrace (拥抱) it. Unlocking our self-improvement power means unlocking ourselves out of the box of thought that is just the way we are. It is such a poor excuse for people who fear change.
Jane always tells everyone that she doesn't have the courage to be around groups of people. She heard her family tell the same things about her to other people. Over the years, that is what Jane has believed. Every time a great crowd come, she steps back and locks herself up in a room. Jane not only believes in her story, but lives it!
Self-improvement may not be everybody's favorite word, but if we look at things in a different way, we might have greater chances of enjoying the whole process instead of counting the days until we are fully improved. Three sessions in a week at the gym would result in a healthier life. Reading books every day would build up knowledge. And only when we are enjoying the whole process of unlocking our self－improvement power will we realize that we're beginning to take things light and become happy.

18． When it comes to the letter grade on your test or homework, you might notice that there is no letter E. Have you ever thought about why that is so?
In the A, B, C, D and F grading system, the first four letters are typically considered passing grades. An F in this system simply stands for "fail". The word "fail" happens to start with the letter F, which seems to leave out the letter E. The fact of the matter is that any letter can mean "not-passing" or "fail". Some schools have U grade for "unsatisfactory", or I grade for "incomplete".
Even with all this said, we should also point out that E grade actually has been used pretty commonly throughout the history of letter grades in the US.
The first college in the US to use a letter grading system like the ones we use today is Mount Holyoke College. In 1897, they began to use the following grading scale:
A: 95—100% (excellent)
B: 85—94% (good)
C: 76—84% (fair)
D: 75% (barely passed)
E: below 75% (failed)
We can see the inclusion of E instead of F.
Gradually, the letter grading system became more popular throughout the US. However, many schools decided to drop the E grade and go straight to F. There is no evidence (证据) to really support this, but one possible explanation is that teachers were worried that some students and parents might mistake E for "excellent".
Why do we have letter grades? Well, part of the reason is that they made grading simpler during a time of great change for schools. As the 20th century began, growing cities and an increase in immigration led to larger school classrooms. Most teachers at that time thought this new letter grading system was an easy, fair and clear way to grade students.
Today, more and more people argue that letter grades don't fully reflect (反映) student learning. However, as teachers try to improve grading methods, many parents continue to favor the letter grades they got as kids. They are familiar (熟悉) and easy for parents to understand. So while they might not be perfect, the letter grades probably aren't going away any time soon.

1. what does an F stand for in the A、B、C、D and F grading system?
                                                                               
2. when was the letter grading system first used in the US college?
                                                                               
3. what is one possible explanation for dropping the E grade?
                                                                               
4. what did most teachers think of the letter grading system in the 20th century?
                                                                               
5. why do many parents still prefer the letter grades today?