The most common use of intelligence test scores is to tell in advance degree of academic success. Such scores are used in some communities as bases for admitting able children to schools at ages younger than normal, and they are very generally used to determine admissions to schools beyond public secondary school. Another use common in elementary schools involves comparing such scores with performances in various subjects to find out children who are working below capacity.

The greatest problem in using intelligence tests for the purpose of prediction is that no dependable criterion of their accuracy exists. The ideal criteria would be objective and reliable achievement tests following instructions in each subject, but there are few such tests, especially at the college level. Studies have shown that correlations(相关性) between intelligence tests and achievement tests in various subjects through secondary school range roughly from 0.5 to 0.8. Such correlations are fairly high, but they do not suggest anywhere near complete agreement.

At the college level there are two major tests used as criteria of admission. By far the more important is the College Entrance Examination, constructed by the Educational Testing Service authorized by the College Entrance Examination Board. These tests are returned to the Educational Testing Service for scoring, and the results are then made available to the various colleges authorized by the students to receive them. The second test of this type is the American College Test, which operates in essentially the same fashion.

Both tests constitute(组成) measures of certain skills, abilities, and knowledge that have been found to be related to success in college. Their correlations with academic success are limited for three outstanding reasons. First, measures of achievement in college are themselves perhaps no more reliable than those in elementary and secondary schools. Second, intellectual factors do not alone determine academic success, especially at the college level. Many students drop out of schools because they are inadequately motivated or because they dislike the instructional programme. Third, correlations are lowered because the use of such tests for denying admission to some students means that the range of scores for those admitted is restricted, and such restrictions tend to reduce correlations.

【推荐3】About ten men in every hundred suffer from color blindness in some way. Women are luckier; only about one in two hundred is affected in this matter. Perhaps, after all, it is safer to be driven by a woman!

There are different forms of color blindness. In some cases a man may not be able to see deep red. He may think that red, orange and yellow are all shadows of green. Sometimes a person cannot tell the difference between blue and green. In rare cases an unlucky man may see everything in shades of green -- a strange world indeed.

Color blindness in human beings is a strange thing to explain. In a single eye there are millions of very small things called "cones". These help us to see in a bright light and to tell the difference between colors. There are also millions of "rods", but these are used for seeing when it is near dark. They show us shape but no color.

Some insects have favorite colors. Mosquitoes (蚊子) prefer blue to yellow. A red light will not attract insects, but a blue lamp will. In a similar way human beings also have favorite colors. Yet we are lucky. With the aid of the cones in our eyes we can see many beautiful colors by day, and with the aid of the rods we can see shapes at night. One day we may even learn more about the invisible (看不见的) colors around us.

【推荐1】The United Nations Environment Program is calling for urgent action to reduce growing risks from chemicals. Better management of chemicals could save millions of lives and billions of dollars. As estimated, 143,000 chemicals are now produced. Yet the report says only a small number of these chemicals have been studied for their effects on human health and the environment. It says death and disability rates are high from the unsafe use of chemical products.

Sylvie Lemmet, director of the UNEP, says poor management of chemicals has a high economic cost. For example, she says the cost is higher than the amount of overseas development aid, or ODA, for health care in sub-Saharan Africa.

She says, “If you look at the estimated cost of poisoning from pesticide (杀虫剂) in sub-Saharan Africa, only the injury and the loss of working time is estimated to be 6.3 billion US dollars in 2009. This is higher than the total ODA that is going to the health part in the same area.”

The UNEP estimates that chemical sales worldwide will increase by around three percent a year until 2050. Chemical production is moving quickly from developed to developing countries. By 2020, chemical production is expected to increase by 40 percent in Africa and the Middle East and 33 percent in Latin America. One of its biggest concerns is pollution of rivers and lakes by pesticide and fertilizer. Other major concerns are heavy metal pollution from the production of cement (水泥) and textiles (纺织品), and dioxin pollution from mining.

The UN report urges the chemical industry and governments to work together to develop safety policies. It says preventing harm costs less than fixing it.

【推荐2】From talking robots and video phones, technology has become so advanced that the previously impossible seems to occur on a daily basis. And yet—we still have no cure for the common cold.

Why can’t we stop the common cold? According to Peter Barlow, a scientist at Edinburgh Napier University, the main challenge lies in the many different types of cold viruses that are produced by the rhinoviruses (鼻病毒). There are at least 160 types. They change so easily that they quickly become resistant to drugs. In other words, a single cure isn’t likely to work on every type of cold.

However, researchers from Stanford University have found a possible answer. They discovered a protein that the viruses need. Without it, they can't spread inside your body.

To identify the gene which produces the specific protein needed by the viruses, researchers used a gene-editing technique to test all genes one by one for thousands of cells. These modified (改变的) cells were then exposed to a range of rhinoviruses which cause the common cold.

All the viruses were unable to copy inside cells without a gene that produces a specific protein, called methyltransferase (甲基转移酶) SETD3.

Then, they tested genetically modified mice, which were completely unable to produce the protein. The mice were able to live healthy, normal lives without the protein.

“Lacking that gene protected the mice completely from the common cold,”   associate professor Jan Carette, from Stanford, told the BBC.

“These mice would always die, but they survived and we saw a very strong protection.”

Carette said the plan is to find a drug which can keep back the protein for a limited time, rather than produce genetically modified humans.

“We have identified a fantastic target that all rhinoviruses require and depend on. Take that away and the virus really has no chance,” said Carette.

【推荐3】An increasing part of the world is becoming artificially lit. Artificial light is often seen as a sign of progress: the march of civilization shines a light in the dark; it takes back the night. But some scientists argue that unnaturally bright nights are bad not just for astronomers but also for nocturnal (夜间的) animals and even for human health.

Now research shows the night is getting even brighter. From 2012 to 2016 the earth’s artificially lit area expanded by about 2.2 percent a year, according to a study published last November in Science Advances. However, the measurement does not include light from most of the energy–efficient LED lamps that have been replacing sodium-vapor (钠气灯) technology in cities all over the world ,says Christopher Kyba, a postdoctoral researcher at the German Research Center for Geosciences in Potsdam.

The new data came from a NASA satellite instrument called the Visible Infrared Imaging Radiometer Suite (VIRS). It can measure long wavelengths of light, such as those produced by traditional yellow-and-orange sodium-vapor street lamps. But VIIRS cannot see the short-wavelength blue light produced by white LEDs. This light has been shown to disturb human sleep cycles and nocturnal animals’ behavior.

The team believes the ongoing switch to LEDs caused already bright countries such as Italy, the Netherlands, Spain and the U.S. to register as having stable levels of lighting in the VIIRS data. In contrast, most nations in South America, Africa and Asia brightened, suggesting increases in the use of traditional lighting.

In 2016, a study showed that one third of the world’s population currently lives under skies too bright to see the Milky Way at night. Between 2012 and 2016 the median nation pumped out 15 percent more long-wavelength light as its GDP increased by 13 percent. Overall, counties' total light production correlated with their GDP.