Read the following article and select the best answer. Article: Anyone who has ever lost keys or money will have wished for a simple but effective way to make sure it never happens again. A US company is trying to help. Using a tiny microchip which is implanted into the arm, they have come up with a replacement for cash or credit cards that cannot be left at home or dropped on the bus. The Verichip is about the size of a grain of rice and works using radio frequency identification technology. At a shop, a radio frequency "reader" would send a signal and the chip in your arm would respond with your unique identity number. That would give the "reader" your financial information, and money could be taken directly from your accounts and you wouldn't even have to reach for your wallet. The company also hopes to include other information on the chip, such as medical records, building security codes and passwords, making life even easier. But not everyone is happy with the developments. Critics say that a lot can go wrong with the chip. A clever thief could build a fake reader that would steal your information without you knowing. So your money could still be stolen. Privacy is a big issue too. Stores, or even the government, only need to track the chip to find out what you buy, how much you spend and where you go. And if you wanted to get rid of your chip, you would need an operation to remove it. Question: Which is true of the Verichip? - Your information on it will always be safe. - Medical records have already been included. - You can easily reach for your wallet using it. - An operation has to be performed to remove it.
An operation has to be performed to remove it.

Read the following article and select the best answer. Article: Most people know precious gemstones by their appearances. An emerald flashes deep green, a ruby seems to hold a red fire inside, and a diamond shines like a star. It's more difficult to tell where the gem was mined, since a diamond from Australia or Arkansas may appear the same to one from the Democratic Republic of the Congo. However, recently, a team of scientists has found a way to identify a gemstone's origin. Beneath the surface of a gemstone, on the tiny level of atoms and molecules , lie clues to its origin. At this year's meeting of the Geological Society of America in Minneapolis, Catherine McManus reported on a technique that uses lasers to clarify these clues and identify a stone's homeland. McManus directs scientific research at Materialytics, in Killeen, Texas. The company is developing the technique. "With enough data, we could identify which country, which mining place, even the individual mine a gemstone comes from," McManus told Science News. Some gemstones, including many diamonds, come from war-torn countries. Sales of those "blood minerals" may encourage violent civil wars where innocent people are injured or killed. In an effort to reduce the trade in blood minerals, the U.S. government passed law in July 2010 that requires companies that sell gemstones to determine the origins of their stones. To figure out where gemstones come from, McManus and her team focus a powerful laser on a small sample of the gemstone. The technique is called laser-induced breakdown spectroscopy. Just as heat can turn ice into water or water into steam, energy from the laser changes the state of matter of the stone. The laser changes a miniscule part of the gemstone into plasma, a gas state of matter in which tiny particles called electrons separate from atoms. The plasma, which is superhot, produces a light pattern. (The science of analyzing this kind of light pattern is called spectroscopy.) Different elements produce different patterns, but McManus and her team say that gemstones from the same area... Question: Why did the U.S. government pass law that requires companies selling gemstones to determine the origins of their stones? - To look for more gemstones. - To encourage violent civil wars. - To reduce the trade in blood minerals. - To develop the economy.
To reduce the trade in blood minerals.

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Read the following article and select the best answer. Article: BEIJING, Jan. 11(Xinhuanet)-- Sleeping a little bit longer a day might help fight against obesity , a recent study shows. The research-- published in the Archives of Internal Medicine along with an editorial by Turek and Northwestern colleague Joseph Bass commenting on it and related research-- after comparing people of normal weight- a body mass index of less than 25- with those who were overweight or _ , found that sleeping for an extra 20 minutes each night could offer a pain-free way to lose weight. Insufficient sleep is linked with changes in hormone levels that may stimulate appetite. A series of studies in recent months have shown that the less people sleep, the heavier they tend to be. American researcher Robert Vorona from Eastern Virginia Medical School in Norfolk and colleagues have now examined the relationship between people's self-reported sleep time per 24 hours and their body mass index(BMI). They found that total sleep time and BMI were inversely correlated was total sleep time decreased, BMI increased, except in the severely obese group." Americans experience insufficient sleep and corpulent bodies. Clinicians are aware of the burden of obesity on patients," the study said. "Our findings suggest that major extensions of sleep time may not be necessary, as an extra 20 minutes of sleep per night seems to be associated with a lower body mass index," it added. "We warn that this study does not establish a cause-and-effect relationship between restricted sleep and obesity (but) investigations demonstrating success in weight loss via extensions of sleep would help greatly to establish such a relationship." In November 2004, researchers from Columbia University in New York City, New York demonstrated a clear link between the risk of being obese and hours of nightly sleep, finding that people aged 32 to 59 who slept four hours or less per night were 73% more likely to be obese than people who slept between seven and nine hours per night. Question: According to the text , the author intends to tell us that _ . - Sleeping a little bit longer a day might help fight against obesity - insufficient sleep is linked with changes in hormone lives - there exists a clear link between the risk of being obeses and hours of nightly sleep - the less people sleep , the heavier they tend to be
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Sleeping a little bit longer a day might help fight against obesity