Article: Gray hair is simply a part of the normal aging process, and the rate you go silver is genetically predetermined. Going gray is not associated with earlier death, and premature graying is not, generally speaking, a sign of an illness or ill health in younger adults. There are, however, some specific health conditions associated with gray or white hair, but for most of us, going gray is just a fact of life. Hair color1 comes from the pigment melanin , which determines your individual shade. Hair without any melanin is pure white. The pigment is produced in cells called melanocytes, which inject pigment into the hair. At some point in everyone's lifetime, these cells slow down and eventually stop producing color1. Scientists have yet to identify the exact mechanism by which melanocyte cell death occurs. A study of more than 4,000 women and men from 20 countries determined that about 75% of people between the ages of 45 and 65 have some gray hair. In general, people of European descent gray earliest followed by Asians and Africans. It's interesting to note that a lucky 1 in 10 has no gray hair by retirement age. Beginning at age 30, your chances of having gray hair go up 10-20% per decade. It may feel like you have more grays after a stressful event, but that's probably because middle age is basically a series of anxiety-ridden events. Between working, raising kids, and caring for older parents, the "sandwich" years of 45-65 can be stressful, especially for women. They are also when we naturally start to look older. At this point, there is still no silver bullet to keep away the grays. Question: Which is not among the reasons for hair turning gray according to the passage? Yes or no, is the answer "Being physically weak."?
No

Article: Excused from recycling because you live in a high rise with a rubbish chute ? You won't be for long. Miami's Mark Shantzis has made it simple for those living in tall buildings to use the chute and recycle too . In Shantzis' Hi-Rise Recycling System, a chute leads to a pie-shaped container with six boxes that can turn around when operated. The system , which fits in the same space as the chute and container now in use, enables glass , plastic , paper , metal , and other rubbish to go into separate boxes . The system is controlled from a board next to the chute door. The board has a button for each class of recycling materials (as well as for unrecyclables). At the press of a button, a microcomputer locks all other floors' chute door and sets the recycling container turning until the right box comes under the chute. The computer also counts the loads and gives a signal by phone when the box is full. And a particular piece of equipment breaks up the nonrecyclables Sorting recyclables before they are collected saves the use of expensive materials recovery equipment which otherwise has to do the sorting . Such equipment often makes recycled materials very expensive, so expensive that tons of recyclables remain wasted . Shantzis believes his system could help recycled materials become more cost-effective. Question: The purpose in writing this text is _ . Yes or no, is the answer "to introduce a recycling system for high rises"?
No

Q: Article: As the new term starts, freshmen around the world are asking the same question: how can I make the best of four years at college? The New York Times received suggestions recently from PhD students and seniors at some of the top universities . Here is their advice. "Many young people today are raised in a protective cocoon ", wrote Tim Novikoff, a PhD student at Comell. "College is a time to explore the world beyond and a chance to learn new things about yourself. Take classes in different subjects. Try lots of different clubs and activities." Remember also to take some time away from campus, suggested Willie Lin, a student at Washington University. " _ " Try to find work assisting a researcher or a professor---this is the advice from Aman Singh Gill, a PhD student at Stony Brook University. And he also said, "With a window into the world of research, you will find yourself thinking more critically, accepting fewer states at face value and perhaps developing a brave sense of what you can accomplish." Many young people can't imagine even a single day without devices such as computers and cell phones. But try to keep yourself off them, cautioned Christine Smallwood, a PhD student at Columbia University. Start by scheduling a few Internet-free hours each day, with your phone turned off. It's the only way you'll be able to read anything serious. "This will also have the benefit of making you harder to reach, and thus more mysterious and fascinating to new friends and acquaintances ," she suggested. Question: This passage is mainly about _ . Yes or no, is the answer "tips from some students for college life"?
A: Yes

Article: Imagine what you could do with a machine that could make things disappear. For inspiration, you could read some books. In the books of J.R.R. Tolkein, Bilbo Baggins finds a ring that can make him disappear. Of course, there's also poor Harry Potter, who used his invisibility cloak to hide from danger. Now that you've got some ideas, it's time for the hard part: building the cloak. To do that, you have to give up science fiction and turn to real science. An invisibility cloak has to cheat anything or anyone who might be watching. In order to understand how something can be seen, it's important to understand how we see. Human beings can only see objects that reflect light waves. These waves enter the eye and are then processed by the brain. However, if an object doesn't reflect light, then the waves don't enter the eye, and the brain doesn't process. So building an invisibility cloak is building something that doesn't reflect light. Cummer was part of a team of scientists from Duke University, including David Smith and David Schurig, who built the world's first version of an invisibility cloak. They had been inspired by the work of a British physicist, John Pendry. He in May said that an invisibility cloak was possible and Pendry was not the only one thinking about a disappearing act. At the same time, a Scottish physicist, UIf Leonhardt published a paper on building invisibility equipment. "It wasn't easy," says Cummer. "As often happens in science and research, it didn't work very well the first time. That first cloak didn't work like Harry Potter's --- the scientists didn't actually see anything disappear. So the research is still under way. " Question: Cummer and other scientists got the idea of building an invisibility cloak from _ . Yes or no, is the answer "the work of a British physicist"?
Yes