You know eating fruit and vegetables is virtuous. But did you know it can also make you look good? People who increased their intake over just six weeks developed a healthy glow and appeared more attractive, researchers found. Scientists at St Andrews University found eating them subtly increased yellow and red pigments in the volunteers' skin. They monitored the food intake of 35 people and took pictures of their faces, arms and hands using a sensitive camera at the start, and after three and six weeks. Increasing their intake of greens by 2.9 portions a day was found to make the person look healthier and an extra 3.3 portion could enhance their attractiveness, when their photographs were rated by others. Fruit and vegetables are rich in carotenoids , which are known to protect against cell damage from pollution and UV rays, and can also prevent age-related diseases including heart disease and cancer. But while it was known eating extreme amounts of certain vegetables such as carrots could turn skin orange, it was not known a small increase was perceptible to others and was seen as _ . A camera measured changes to the skin's redness, yellowness and lightness, and found it significantly changed in people who naturally increased their intake. These changes were not evident at three weeks. Using light sensors, the researchers showed these red and yellow hues(,) were linked with the levels of carotenoids in their skin. There are hundreds of carotenoids but those thought to have the most dramatic effect are lycopene which gives tomatoes and red peppers their red color1 - and beta-carotene found in carrots as well as broccoli, squash, and spinach. Skin color1 is also affected by chemicals called polyphenols , found in apples, blueberries and cherries, which cause blood rush to the skin surface. The red and yellow color1s were related to _ in their skin. A) the contents of intake B) the levels of carrots C) the time of eating fruit and vegetables D) the amount of carotenoids
D
Since American students have been introduced into the era of the Massive Open Online Course, the opportunity for cheating appears greater than ever. The all-knowing Google search engine is within easy reach. So how can a teacher handle such a large number of examinees so far away, let alone searching out cheaters taking tests across the Internet? Using technology, of course. While special services via webcam and cheating detecting software have been developed now, Mettl, an online company, has developed advanced techniques for netting cheaters, which the company claims are even more reliable and easier to use. Whatever small attempt to cheat, he or she will be found out. Mettl has adopted a mass of technologies on its test-taking platform, creating a mini monitoring state in an exam. Here's how it works: A test-taker signs on to Mettl and selects his/her exam from the site's library of pre-loaded tests. Facial and keystroke recognition technology confirm the person that has signed in is the very person, and the system records both the test-taker (through the webcam) and the test-taker's screen throughout the test. Mettl's technology uses the test-taker's webcam to detect how many people are using the computer. Soon, it will track eye movement well enough to sense whether the test-taker is looking away from the screen, perhaps to consult a smart phone or a friend in secret. Mettl also monitors the test-taker's screen and can detect when the test-taker has changed a computer or moved from the test. The system will soon be able to record sound, detecting whether the test-taker is talking or being talked to. If any wrongdoings are detected, the system flags the incident and reports it back to the test's administrator. This can bring any number of things, depending on the test-giver's wishes: a complete shutdown of the exam, a warning message that appears on the test-taker's screen, even human instructions from the control center. Mettl is hoping its technology will help it break into the country's big MOOC markets. How can Mettl help to get rid of cheating online? A) By equipping teachers with cameras. B) By asking test-takers to sign in. C) By providing different tests at a time. D) By recording the test-takers' behaviors.
D
Q: Tiny transmitters fixed on the backs of the blue-green bees have allowed scientists to follow the insects as they fly for miles in search of rare flowers. Working in Panama, scientists caught 17 bees of the common species and fixed a 300 milligram radio light onto the back of each. The signals they sent out were used to follow their movements in and around the forest where they lived. Professor Martin, from Princeton University, US, and the Max Planck Institute for Ornithology in Germany, said, "By following the radio signals, we discovered that male bees spent most of their time in small centre areas, but could take off and visit areas farther away. One male even crossed over the shipping lanes in the Panama Canal, flying at least 5km, and returned a few days later." Researchers have struggled to follow the movements of bees before, following bees marked with paint or using radar which doesn't work well in forests. "Carrying the transmitter could reduce the distance that the bees travel, but even if the flight distances we record are the shortest distances that these bees can fly, they are impressive, long-distance movements," said Dr. Roland Kays, from New York State Museum, a co-author of the research published today in the on-line journal. "This result helps to explain how these bees' pollination can be so rare." Pollination by bees and other insects is the key to the diversity and continued growth of flowers and trees in some forests. The new study is the first to use radio transmitters to follow bees in a forest. Similar research may now be carried in temperate forests, where bees also play a vital role. The main purpose of the passage is to _ A) call on people to protect the bees for the environment B) explain why the bees fly far away in search of flowers C) introduce a modern way to follow the bees to readers D) encourage the public to support the scientists' research
A: C
(Question)
Almost five years ago, I announce to my loved ones I was to become a Mrs Naturally. I then began to wonder about the perfect wedding dress, hoping that it would fit me. Even at the age of 22, I had gone through my share of dieting. I am an emotional eater and I knew that at 5 feet 5 inches tall and weighing 180 pounds, I wasn't at my healthiest. My mother had been doing Weight Watchers for some time and was rapidly seeing results. I took my mother's advice about Weight Watchers. She shared her books with me and explained the program: estimate your daily point target based on your weight and other factors, write down everything you eat and move! The longer I stuck to it, the more I noticed a difference in the way I enjoyed food. I soon began to like eating fruit and vegetables for snacks instead of chocolate bars and chips. My mother and I went on walks together and kept each other in check. Unsurprisingly, I lost twenty pounds soon and looked amazing in my wedding dress. I bought healthy food instead of ice creams and faithfully kept a food journal. I exercised on my Wii Fit and took evening walks. Since I had a hard time finding something healthy to eat, I bought a Weight Watchers cookbook and used it to prepare our meals. I used small plates and bowls to trick myself into believing there was more food than the serving size. Now I'm 28 and weigh 120 pounds, but I still need to lose some weight. I know the challenge is worthwhile. I must insist on it and tomorrow is another day. What do you know after reading the passage? A) The writer has make a great effort to lose weight. B) The writer doesn't have strong will power. C) The writer doesn't believe she can look amazing. D) The writer doesn't know how to cook.
(Answer)
A