Undercover Wings

The nocturnal（夜间活动）dot-underwing moth（蛾）may use shape -shifting patterns on its wings as a way to attract mates in the dark. In a study published last September in Current Biology, scientists report the    1    on males' forewings of three patches（色斑）that change darkness and size when viewed from particular angles. In females, the entire forewing darkens.

Although butterfly and moth species that are active during the day are known to employ visual effects to communicate, researchers had thought their nocturnal cousins relied almost    2    on chemical signals because of the lack of light. But these    3    wing patterns, now found for the first time in a nocturnal moth, suggest the insects may also use visual signals. Because only the males have this pattern, researchers say it is likely a（n）    4    selected mechanism.

Jennifer Kelley, an ecologist based at the University of Western Australia, and her colleagues first noticed the visual phenomenon while looking at museum moth specimens（标本）for another project. "As soon as we figured the effect was angle-    5    , we knew that to understand how it works, we had to understand the    6    physics," Kelley says. The group contacted Gerd Schröder-Turk and Bodo Wilts, who are physicists at Murdoch University in Perth and the Adolphe Merkle Institute in Switzerland respectively.

Together the researchers found that when the wings are viewed from above, they    7    available light directly, like a dull mirror. When viewed from an angle, however, they let some of the light through to reveal a deeper layer of darkness, which    8    as patches on the male's wings. If the insects were to beat their wings    9    —a common behavior among males approaching potential mates—the patches would flash on and off, creating a striking signal even in very    10    light.

Animal Testing

Food and Drugs Administration (FDA) is responsible for ensuring that cosmetics are safe and properly labeled. Although FDA has never     1     required the use of animals in testing cosmetics for safety, animal testing is often used to establish product safety by manufacturers     2     to launch new products.

In some cases, after considering potential alternatives, companies may still determine that animal testing is necessary to ensure the safety of a(n)     3     or ingredient. FDA also supports and sticks to the applicable laws,     4     and policies governing animal testing. Moreover, in all cases where animal testing is used, FDA advocates that research and testing should get the maximum amount of useful scientific information from the minimum use of animals, and     5     the most humane (人道主义) methods available within the limits of scientific capability.

Animal testing seems     6     in the current cosmetic industry, but many people believe that prior to the use of animals, consideration should be given to the use of scientifically valid (有效的)     7     methods to whole-animal testing. Actually, in the late 1990, FDA joined with other thirteen federal agencies in finding possible ways to     8     animals in tests. FDA has been supporting the development and use of alternatives to whole-animal testing and thus has been     9     considerable amounts of money into research on animal substitutes.

Besides American scientists scientists in other countries are making efforts swell. Scottish University are now trying to create the world’s first     10     human liver for drug testing so as to dramatically cut the number of live animals used and get life-saving medicines into the clinic faster.

An addiction is an activity or substance we are eager to experience repeatedly, and for which we are willing, if necessary, to pay a price. Common addictions involve alcohol, cigarettes, food, drugs, gambling, etc. This article discusses the concepts which can help cope with addictive behavior.

Usually,     1    minor addictions, such as watching too much television, or lying in bed on weekend mornings, are not even considered addictions, because the price paid for engaging in them is not high, On the other hand, we tend to use the term "    2    " to describe the person who, at least in the eyes of others, continues to be addicted in a behavior long after it has become clear that the     3    price being paid was not worth the benefit. The individual who has lost his career, house, family and friends because of cocaine use, but is     4    to consider stopping, is an unfortunate example.

Negative addictions     5    from those with very minor negative consequences, to those as serious as the cocaine addict just mentioned, with much area in between. Although it is not     6    true that a negative addiction grows stronger over time, a constant level of addictive behavior can lead to an increasing level of negative consequences.

You may be surprised to learn that addictions can also be considered positive. Positive addictions are those in which the benefits     7    the price. A common example would be the habit of regular exercise. The price of membership in a gym, the time     8    and any clothing expense is outweighed by the benefits of better health, energy, self-confidence and appearance. As with negative addictions, positive addictions may not get stronger over time, and there is a broad range of how much benefit is actually obtained.

What is common to both positive and negative addictions is the urge to engage in the addictive behavior, and the satisfaction that is     9    when the urge is acted upon. The urge is a state of tension and     10     that is experienced uncomfortably as a desire for the substance or activity. Because we experience relief when the urge is acted upon, there is an increased likelihood that we will act on the urge again.

When did the voice inside your head start talking? I became       1     of mine at about the age of 15. At night, I sometimes found it difficult to get to sleep because there was so much “mind chatter” inside my head.

In fact, mind chatter is quite common for human beings. Usually, whenever our       2     isn’t occupied, a stream of mental associations flows through our muds— thoughts about the future or the past, daydreams about alternative realities, or friends or celebrities. We often call this mental activity “thinking”, but this isn’t really accurate.

Real thinking suggests something active over which we have conscious(有意识的)     3    . It happens when we consciously use powers of reason and logic to make decisions and plans, organize our lives, solve problems and so on. But mind chatter isn’t like this. It’s random(随机的)and     4    , running through our head regardless of our desires and distracting us.

For example, imagine you’re thinking about what elective course to take for the next school year. As you are considering them, thoughts about your favorite subjects flood in,     5     you of a project that you really like. This makes you remember chatting with friends about some documentaries that       6     to young people. Suddenly, you remember the upcoming science fair and you worry about       7     your time. All these thoughts leave you struggling to       8    , and you end up seeking advice from classmates.

However, it’s       9     to expect to silence our mind chatter altogether. It’s such a natural part of our minds that it won’t disappear. We should accept it and treat I t as a kind of physiological process that takes place inside us but is not part of our identity. We don’t get our sense of identity from our digestion or blood circulation, so why should we       10     with the voice inside our head?

【推荐3】Directions: Fill in each blank with a proper word chosen from the box. Each word can only be used once. Note that there is one word more than you need.

No child or young athlete should be subjected to genetic testing to find sporting talent or improve performance, conclude the experts in a statement published in the British Journal of Sports Medicine.

The scientific evidence on the effectiveness of these     1     tests is simply far too weak to back their use, says the experts in the fields of genomics, exercise, sports performance, etc. While the science of genomics has advanced rapidly over the past decade, the ability to interpret the meaning of genetic test results is still at a relatively early stage.

But that has not stopped the growth of the “direct to consumer” genetic tests, which claim to be able to spot children’s athletic talents or tailor training to     2     performance. This fast - growing market has caused fears that the still limited level of knowledge on the genetics of sports performance is being     3     for commercial gain.

To inform the statement, the panel looked at the availability of DIY genetic tests. It found 39 companies     4     tests associated with sport or exercise performance or injury - almost twice as many as in 2018.

The claims included: “    5     your training based on your sports genetics,” “Give parents and coaches early information on their child’s genetic     6     for success for sports,” and “We use your DNA results to help you lose fat, build muscle, get fitter.”

But the     7     of any good scientific data to guide selection of which variants to test weakens the value of multiple testing. Besides, while there is some evidence to suggest a link with enhanced physical performance, it is very weak, making the     8     value of these tests “actually zero,” says the statement.

The statement emphasizes the     9     of change in gene sequencing technology has got much faster than regulation. And it points out the importance of counselling before any genetic test is taken.

“While further evidence will undoubtedly emerge around the genetics of sport performance in the future, the data are currently very     10    . Therefore, in this stage of limited knowledge, no child or young athlete should be exposed to genetic testing to define or alter training or for talent identification aimed at selecting gifted children or adolescents,” it concludes.