Air traffic controllers in the US have been advised to take 26-minute naps  , after a series of accidents involving workers falling asleep. Now the National Transportation Safety Board (NTSB) is calling for "controlled naps" during nightshifts  . NTSB member Mark Rosekind said that a 26-minute nap would improve performance by 34%. He believes that beyond the aviation   industry, other professions, such as motoring and machinery, also carry obvious risks. But other experts doubt whether 26 minutes is the appropriate napping time. It's a bit too long and risks you falling into a deep sleep, says Jim Horne, director of the Sleep Research Council. He said, "A nap of about 15 minutes is best; once you get beyond 20 minutes, you risk a deep sleep and you can be much more tired when you wake up. Therefore, we suggest that a nap be combined with a cup of coffee so that you can enjoy an effective sleep before the caffeine   takes effect in 20 minutes. However, this method only works on those who have had a poor night's sleep. If you haven't had a sleep the night before, this method won't be enough to make you fresh."  Health writer, Linda Wasmer Andrews, also believes that 26 minutes is too long. She says a nap between 10 and 20 minutes is enough, and the timing of the nap is also important. Putting your head down too early means your body may not be ready to sleep yet, but a nap that is too late in a day might make it harder to fall asleep. Early afternoon is often the best time, between l pm to 3pm, when people experience a post-lunch decrease in energy. What does the text mainly talk about? A) People who need a nap. B) How long a nap should last. C) When people should take a nap. D) The reason why people need a nap.
B


Every girl wants to have a great-looking tattoo   design that makes them more attractive. Small and lovely tattoo designs are the path to go for girls planning to get tattooed for the first time. Nowadays, more and more females are getting a tattoo inked on their body. In the last fifteen years, tattoos have grown from being a sign of rebelliousness and trouble to a state of popular acceptance as a mark of fashion. Tattoos are permanent so you need to be sure that you like it before getting one. A great way is to have small tattoos that look beautiful as well. You can get a cherry blossom tattoo on the foot, perhaps, a hibiscus flower on the shoulder or a lovely butterfly on the lower stomach; whatever design you choose, it can definitely add to your attractiveness and charm. Deciding to get a tattoo needs careful thought and reflection. Otherwise, you could make some serious tattoo mistakes. Try to avoid big and obvious designs if possible. Another important part of choosing a tattoo design is the location. What part of the body do you want it on? Choosing a hidden location can often make the tattoo the perfect adornment  . As for professional women, tattoos should normally be where they can be hidden. Most importantly, no matter what tattoo design you choose the final goal is that the design should be something you like. If you are into the tattoo and really feel passionate about it you will carry yourself in a different manner when you get it inked on your body. What is the author's attitude towards girls' getting a tattoo? A) He is against girls' doing so B) He thinks professional women should not get tattooed C) He is in favor of it as long as it is done probably D) He calls on all the girls to do so
C


Q: Probably no other musical instrument is as popular as the guitar around the world. Musicians use the guitar for almost all kinds of music. Country and western music would not be the same without a guitar. The traditional Spanish folk music called Flamenco could not exist without a guitar. The sound of American blues music would not be the same without the sad cry of the guitar. And rock and roll music would almost be impossible without this instrument. Music experts do not agree about where the guitar was first played. Most agree it is ancient. Some experts say an instrument very much like a guitar was played in Egypt more than 1,000 years ago. Most experts say that the ancestor of the modern guitar was brought to Spain from Persia sometime in the 12thcentury. The guitar continued to develop in Spain. In the 1700s it became similar to the instrument we know today. Many famous musicians played the instrument. The famous Italian violins Niccole Paganism played and wrote music for the guitar in the early 1800s. Franz Schubert used the guitar to write some of his famous works. In modern times Spanish guitarist Andres Segovia helped make the instrument extremely popular. In the 1930s, Les Paul began experimenting to make an electric guitar. He invented the solid-bodied electric guitar in 1946. The Gibson Guitar Company began producing its famous Les Paul Guitar in 1952. It became a powerful influence on popular music. The instrument has the same shape and the same six strings   as the traditional guitar, but it sounds very different. Les Paul produced a series of extremely popular recordings that introduced the public to this music. Listen to this Les Paul recording. It was the fifth most popular song in the United States in 1952. It is called "Meet Mister Callaghan." According to most experts, the guitar developed into a modern form like today in   _  . A) Egypt B) Persia C) Spain D) Italy
A: C


(Q).
Express delivery: How you can buy your groceries from a virtual supermarket Aug, 1st, 2011 Daily Mail A "virtual supermarket" consisting of posters of goods put on platform walls is set to be introduced at London Underground stations. Passengers "shop" by scanning QR--Quick Response--codes of the items they want to buy using their smart phones. These goods are later delivered to their home address. Supermarket giant  Tesco successfully trialed the hi-tech store in a South Korean underground station and there are now plans to bring the concept to Britain. NYPD to Scan Facebook, Twitter for Trouble Aug, 11th, 2011 Forbes The New York Police Department announced it will form a new unit to search social media as part of its law enforcement  efforts, responding to the criminals' growing use of these sites to plan and celebrate illegal activities. The NYPD unit created particularly to _ social media sites like Facebook, Twitter, and BlackBerry messenger for information on planned crimes and their criminals. Space Junk  reaching "tipping point", report warns Sep 3rd, 2011 Toronto Sun The amount of debris  orbiting the Earth has reached "a tipping point" for crashes, which would produce more debris that may be dangerous to astronauts and satellites, according to a US study. According to the US Space Surveillance Network, the number of orbital debris jumped from 9,949 in December 2006 to 16,094 in July 2011. we can learn from the news that_. A) people with mobile phones can shop at London Underground stations B) Facebook, Twitter, and BlackBerry messenger are not popular in the US C) the amount of space junk has more than doubled in the past few years D) more and more criminals are using social media sites for crimes
(A).

D