A good joke can be the hardest thing to understand when studying a foreign language. As a recent article in The Guardian newspaper noted, “There's more to understanding a joke in a foreign language than understanding vocabulary and grammar.”

    Being able to understand local jokes is often seen as an unbelievable ice-breaker for a language learner eager to form friendships with native speakers. “I always felt that humor was a ceiling that I could never break through,” Hannah Ashley, a public relations account manager in London, who once studied Spanish in Madrid, told The Guardian, “I could never speak to people on the same level as I would speak to a native English speaker. I almost came across as quite a boring person because all I could talk about was facts.”

    In fact, most of the time, jokes are only funny for people who share a cultural background or understand humor in the same way. Chinese-American comedian Joe Wong found this out first-hand. He had achieved huge success in the US, but when he returned to China in 2008 for his first live show in Beijing, he discovered that people didn't think his. Chinese jokes were as funny as his English ones.

    In Australia, meanwhile many foreigners find understanding jokes about sports to be the biggest headache. “The hardest jokes are related to rugby because I know nothing about rugby,” said Melody Cao, who was once a student in Australia. “When I heard jokes I didn't get, I just laughed along.”

    In the other two major English-speaking countries, the sense of humor is also different. British comedian Simon Pegg believes that while British people use irony (反话)—basically, saying something they don't mean to make a joke—every day, people in the US don't see the point of using it so often. “British jokes tend to be more subtle and dark, while American jokes are more obvious with their meanings, a bit like Americans themselves,” he wrote in The Guardian.

    Dictionaries are not closed books. There is still plenty of room for more words in these great vocabulary authorities.

    Dictionaries are not closed books. There is still plenty of room for more words in these great vocabulary authorities. New words are continually being created and added to our language. And many of today's word experts can credit a famous mathematician with the creation of the method by which they develop many new words. The mathematician was an Englishman named Charles L. Dodgson. In addition to working with figures, Dodgson wrote books. His imaginative stories and poems have made Dodgson beloved to generations of readers. We know him, however, not by the name of Dodgson but by his pen name, Lewis Carroll.

    Lewis Carroll has delighted countless readers, young and old, with Alice in Wonderland, Through the Looking Glass, and numerous poems. In these works, Carroll developed dozens of nonsensical words such as "chortle" and "galumph". Many of these words are combined naturally with more common words in the English language. Carroll referred to his made-up words as "portmanteau" words, named after a kind of leather suitcase that opens into two compartments. The name was well suited, because most of Carroll's words had two compartments. Rather than being entirely fabricated（虚构）, they were usually made from the combined parts of two different words. A "snark", for example, clearly came from a snake and a shark.

    Although Carroll died long ago, his technique continues to be used today. We clearly see his influence in such words as smog, brunch, and guesstimate.

    There might be as many as 10 million species of complex life on this planet today —— a huge number. But add up all of the complex species that ever lived and some biologists think the grand total would be about five billion. The estimate leads to an astonishing conclusion: a staggering 99% of species are not around any more. They have been driven to extinction.

    More species are joining the ranks of the extinct every year. Many scientists believe we are living through an episode of remarkably rapid extinction, on a scale that has been seen only five times in the last half a billion years.

    They call this current episode the sixth mass extinction —— a large, global decline in a wide variety of species over a relatively short period of time. And they tend to agree that humans are the main cause.

    Over-hunting, overfishing, and human-driven habitat loss are pushing many species to the brink. In fact, we have changed the planet so much that some geologists are now suggesting that we have entered a new phase in Earth's history; an epoch they call the ＂Anthropocene＂. By 2100, it is expected that humans will have caused the extinction of up to half of the world's current species.

    Because we are living through this extinction, it is relatively easy for us to study the driving forces behind it. But how do we determine what caused other mass die-offs that happened long ago? To do so we have to look at what archaeologists, palaeontologists, geologists and other scientists have concluded from the evidence they have gathered.

    The trouble is, those scientists do not always agree with one another —— even about the most recent extinction event. As well as the five-or six- mass extinctions, there have also been many smaller extinctions.

    One of these mini extinction events happened towards the end of the Pleistocene, a few tens of thousands of years ago. It is sometimes called the ＂megafaunal＂ extinction because many of the species it claimed were particularly large animals, weighing more than 97lb (44kg). However, its cause remains a debate amongst scientists.

    Cold weather during winter months may keep many people from leaving home and running in the open air.

    However, a new study shows that the drop in temperature is a good reason to run. In fact, researchers say, running in cold weather helps improve one's performance.

    Many people say running in the winter can be difficult. Two reasons are the low temperatures and bitter winds. Yet many runners might find it easier than running in hot weather.

    That could be because lower temperatures reduce stress on the body. When you run in cold weather, your heart rate and the body's dehydration (脱水) levels are lower than in warmer conditions. The body needs less water on a cold day than in warm weather.

    This information comes from sports scientists at St. Mary's University in London. John Brewer is a professor of applied sport science at St. Mary's.

    For this study, he and other researchers put a group of people into a room they called an "environmental chamber." The researchers then recreated summer and winter weather conditions in the room. The test subjects were asked to run 10,000 meters under both conditions. Brewer says he and his team recorded biological measurements of the runners.

    "We've got a group of subjects into the environmental chamber, we've changed the conditions to replicate the summer or winter and we've got them to run a 10km under both of those conditions and taken various measurements on each runner while they've been completing their 10km."

    Brewer says every movement runners make produces heat. He explains that one way in which we lose heat is by sweating. The body loses heat through droplets of sweat. He says the body also loses heat by transporting the blood to the surface of the skin.

    It is well known that male humpback whales(座头鲸)are skilled singers. Their songs are thought to attract females in high frequency sounds while to compete with other males in low frequency sounds. Research led by the Wildlife Conservation Society has now made a new discovery.

    The study looked at the songs of two humpback whale populations, based on sound recordings collected from 2013 to 2018. One group was based in the South Atlantic, off the coast of Gabon, and the other in the Indian Ocean near Madagascar.  Analysis of the recordings showed that the two groups picked up musical ideas from each other and borrowed phrases and themes into their latest song. This suggested that the males from the two groups came into contact with each other over the five years and shared songs.

    To uncover this musical cooperation, researchers recorded the songs and transcribe them into more than 1,500 individual sounds and patterns, or song units.  They found that the units were composed into larger phrases, which were then repeated to form themes. These themes were sung for hours at a time, or even days. By 2018, both populations have been singing largely the same songs.

    "This similarity in the songs shows that these two populations come into closer contact than other southern populations, explains Dr Melinda Rekdahl, leading author of the study. As well as being an interesting phenomenon, she explains that those songs allow even greater insight into the workings of the humpback whale populations.