Last week my youngest son and I visited my father at his new home in Tucson, Arizona. He moved there a few years ago, and I was eager to see his new place and meet his friends.

    My earliest memories of my father are of a tall, handsome, successful man devoted to his work and family but uncomfortable with his children. As a child I loved him, as a school girl and young adult I feared him and felt bad about him. He seemed unhappy with me unless I got straight A's and unhappy with my boyfriends if their fathers were not as "successful" as he was. Whenever I went out with him on weekends, I used to struggle to think up things to say, feeling on guard.

    On the first day of my visit, we went out with one of my father's friends for lunch at an outdoor cafe. We walked along that afternoon, did some shopping, ate at the street table, and laughed over my son's funny facial expressions. Gone was my father's critical（挑剔的）air and strict rules. Who was this person I knew as my father, who seemed so friendly and interesting to be around? What had held him back before?

    The next day my dad pulled out his childhood pictures and told me quite a few stories about his own childhood. Although our times together became easier over the years, I never felt closer to him at that moment. After so many years, I'm at last seeing another side of my father. And in so doing, I'm delighted with my new friend. My dad, in his new home in Arizona, is back to me from where he is.

    18-year-old Kayla Perkins explains what is in her bedroom, "I throw something on the floor and I know right where it is." However, her parents, Steve and Deborah Perkins, of McKinney, Texas, haven't caught on. Even Kayla admits that, at the worst, her room is a mess.

    Most families at some point have at least one child whose room looks like a landfill(垃圾堆). The mess can disturb the whole household. Dirty clothes pile up; dirty dishes get lost in the mess and smell bad; homework is lost; and valuable things are ruined.

    Some parents let it go, believing that a bedroom is private space for children to manage as they wish. Others lecture their children, offer rewards for cleaning, or punish them when they don't. What doesn't work, parenting experts say, is constant lectures, verbal(口头的,言语的) threats or getting very angry. Mrs. Perkins says they picked up all the clothes on Kayla's floor and hid them. They cleaned everything up. When Kayla came back to a bare bedroom, there was screaming and shouting, "How can I live without my clothes?" Mrs. Perkins asked Kayla to earn her clothes back by doing housework. These days, she keeps her room clean.

    Humour can help, too. For example, since Jessica, the 14-year-old daughter wasn't bothered by the dirty clothes all over her floor, the whole family started using her room as a place to store dirty clothes. Her attitude changed after her family did that. By the time she gave in and cleaned up her room a few days later, even she was laughing.

Parenting expert, Jim Fay, also recommends that parents first ask children in a nice way to clean up and agree on a reasonable time limit. Children often behave better if you treat them in the way you would want to be treated by your boss at work—with respect and high expectations.

    If English means endless new words, difficult grammar and sometimes strange pronunciation, you are wrong. Haven't you noticed that you have become smarter since you started to learn a language?

    According to a new study by a British university, learning a second language can lead to an increase in your brain power. Researchers found that learning other languages changes grey matter. This is the area of the brain which processes information. It is similar to the way that exercise builds muscles.

    The study also found the effect is greater when the younger people learn a second language. A team led by Dr. Andrea Mechelli, from University College London, took a group of Britons who only spoke English. They were compared with a group of "early bilinguals" who had learnt a second language before the age of five, as well as a number of later learners.

    Scans showed that grey matter density (密度) in the brain was greater in bilinguals than in people without a second language. But the longer a person waited before mastering a new language, the smaller the difference.

    "Our findings suggest that the structure of the brain is changed by the experience of learning a second language," said the scientists.

    It means that the change itself increases the ability to learn.

    Professor Dylan Vaughan Jones of the University of Wales, has researched the link between bilingualism and maths skills. "Having two languages gives you two windows on the world and makes the brain more flexible (灵活的)," he said. "You are actually going beyond language and have a better understanding of different ideas."

    The findings were matched in a study of native Italian speakers who had learned English as a second language between the ages of two and thirty-four. Reading, writing, and comprehension were all tested. The results showed that the younger they started to learn, the better. "Studying a language means you get an entrance to another world," explained the scientists.

Plastic is everywhere, from the Arctic ice to vital organs in the human body. In fact, previous estimates suggest that the average person swallows a credit card-worth of microscopic plastic particles(颗粒) every week. But new research shows that this could actually be an understatement. 

Microplastics are plastics smaller than 5 millimeters, found in industrial waste, beauty products, and formed during the degradation of larger plastic pieces. Over time, they break down into even smaller nanoplastics. These tiny particles can pass through our intestines and lungs into our bloodstreams, reaching vital organs like the heart and brain. 

While the idea of eating plastic is unsettling in itself, the major concern here is that these plastic particles contain chemicals that can interrupt our body's natural release of hormones, potentially increasing our risk of reproductive disorders and certain cancers. They can also carry toxins(毒素) on their surface like heavy metals. 

In the past, researchers have shown bottled water can contain tens of thousands of identifiable plastic fragments in a single container. However, until recently, only the larger microplastics were detectable with available measuring tools, leaving the area of nanoplastics largely a mystery. 

Using Raman microscopy (显微镜学), capable of detecting particles down to the size of a flu virus, the team measured an average of 240, 000 particles of plastic per liter of bottled water, 90 percent of which were nanoplastics, a revelation 10 to 100 times larger than previous estimates. 

These plastics likely originate from the bottle material, filters used to "purify" the water, and the source water itself. "It is not totally unexpected to find so much of this stuff, " the study's lead author, Columbia graduate student Naixin Qian, said in a statement. His team hopes to expand their research into tap water and other water sources to better inform our exposure to these potentially dangerous particles. "The idea is that the smaller things get, the more of them I reveal, " he added.

A teenager needs to have a sense of independence in their life to feel secure(安全的). To some teenagers independence means a lot to them, and I think that some parents don't allow their teenagers enough independence.

Independence has something to do with freedom. Some kids are not allowed to go anywhere alone, and the only thing their schedule includes is going to school, coming home, going to sleep, and repeating the process the next day. Parents tend to be afraid that their kids can get hunt if they go outside into the world. But if parents control their kids too much, they may never learn to live on their own. The best way for a teenager to learn lesson is through experience. I think it is beneficial for teenagers to have freedom.

Teenagers' lack of freedom can also stop them from having good friendship at school. Some might say this is a good thing, because it helps them focus more on their school work. I argue that this can only discourage them not to do their school work. Some parents do not allow their children to be around their friends outside the school, thinking that this will get them into trouble. But I don't think so. Instead, isn't this a good reason for parents to get their children a cellphone? Cellphones allow teenagers to stay in touch with their parents, and communicate with friends.

Privacy is another issue between parents and their teenagers.Teenagers tend to enjoy relaxation by themselves in their own room. This also gives them a sense of independence. It often annoys teenagers when their parents enter their room when they are not home. I know that my mom always goes in my room when I'm not home, and this has brought me to the point where I have asked many times to get a lock on my door.

Donna Strickland was awarded the 2018 Nobel Prize in Physics jointly with Arthur Ashkin and Gérard Mourou.It's the first time in 55 years that a woman has won this famous prize, but why has it taken so long? We look at five other pioneering female physicists — past and present — who actually deserve the prize.

Jocelyn Bell Burnell

Perhaps the most famous snub (冷落): the student Bell discovered the first radio pulsars in 1967, when she was a PhD student at Cambridge.The Nobel Prize that recognised this landmark discovery in 1974, however, went to her male supervisor, Antony Hewish.Recently awarded a £2.3 million Breakthrough Prize, which she gave away to help under-represented students, she joked to The Guardian, "I feel I've done very well out of not getting a Nobel Prize."

Lene Hau

Hau is best-known for leading the research team at Harvard University in 1999 that managed to slow a beam of light, before managing to stop it completely in 2001.Often topping Nobel Prize prediction lists, could 2019 be Hau's year.

Vera Rubin

Rubin discovered dark matter in the 1980s, opening up a new field of astronomy.She died in 2016, without recognition from the committee.

Chien-Shiung Wu

Wu's "Wu experiment" helped disprove the "law of conservation of parity".Her experimental work was helpful but never honoured, and instead, her male colleagues won the 1957 Nobel Prize for their theoretical work behind the study.

Lise Meitner

Meitner led groundbreaking work on the discovery of nuclear fission.However, the discovery was acknowledged by the 1944 Nobel Prize in Chemistry, which was won by her male co-lead, Otto Hahn.