Bees and other pollinators（传粉者）  use smells to track down fresh flowers. Air pollutants can weaken those scents（气味）.  Scientists had worried this might make it harder for some pollinators to find a meal.

    Many animals help pollinate plants. Species that do this include bees, butterflies, etc. But for many reasons, the pollinators available to help plants in this way are decreasing. Scientists think a loss of habitat（栖息地）can be one factor. Diseases and exposure to poisonous chemicals also count.

    Jose Fuentes points to air pollution as another possible factor. He's an atmospheric scientist at Pennsylvania State University. In an earlier study, he showed some air pollutants could weaken or destroy scents emitted(发出)by flowers.

    Searching for a meal leaves pollinators out in the open and at risk of becoming other animal's lunch. And any time spent hunting food is time away from their duties back home, like protecting a hive（蜂巢）or nest, explains T'ai Roulston. He's an insect biologist at Virginia University. Roulston worked with Fuentes on the new study.

    In the study, the researchers focused on five kinds of representative scent molecules(分子)plants emit. One molecule they looked at, for example, is called beta-myrcene. Many flowers give off this chemical into the air.  Normally, this gas can travel some 800 meters from its flower source. But in polluted air, this same molecule could travel only half as far.

    Worse still, air pollution might do more than just weaken scent plumes（气味烟云）．Chemical reactions between air pollutants and plumes may transform the flowers' smells, creating new scents. And these scents may be unrecognizable to pollinators.

    That's certainly Fuentes' concern.  So, he says his next research project will look at how insects handle any new flower scent. "It's possible that some insects will change ways to detect and use these new molecules to find food," he says.

    When was the last time someone unexpectedly did something nice for you? Not someone you knew, but a total stranger? It's happened to me a few times, but two instances really stand out.

    A few years ago, I was dining in a restaurant with a friend who kept talking about himself, completely not aware of the fact that I was sitting there in misery. It wasn't my friend's talks that made me suffer. I was recovering from a broken heart, and just sitting down to dinner reminded me of my last relationship. I could have burst into tears right there at the table.

    When we picked up the check, the waitress said, ―Your meal was already paid for.  My friend and I didn't have a clue how it happened. Then I remembered a man coming in out of the corner of my eye. He was dressed in mostly white, sat down at the bar, had a beer, and stayed for maybe ten minutes. The waitress said, ―Yes, the gentleman in white paid for you.  It felt like an angel was saying ―I see you, honey. It's going to be okay.

    Just last year, I was running a half-marathon. With just 1 mile to go, I was out of gas. Runners call it ―hitting the wall . I thought I couldn't move another inch. Out of nowhere, a stranger came up to me and said, ―What's your name, sweetie? Jennifer? Okay, Jennifer, let's go! Come on! It's just around the corner! You can do it!  And he ran with me until I picked up my pace. I found him at the finish line to thank him for the encouragement only to learn he wasn't even supposed to be in the race that day.

    I still shake my head when I think of these momentary angels that came to me at my point of need.

    Do you have any experiences like these?

    Before the coming of the first settlers from Europe, Canada's local people had discovered a new kind of food—maple sap(汁液)，which they gathered every spring. According to many historians, the maple leaf began to serve as a Canadian symbol as early as 1700.

    In 1834, the first St. Jean Baptise Society in North America made the maple leaf its sign. In 1836, Le Canadian, a newspaper, referred to it as a suitable symbol for Canada. In 1860, the maple leaf was used widely in decorations for the visit of the Prince of Wales. Alexander Muir wrote The Maple Leaf Forever in 1867; it was regarded as the national song for several decades. The army uniforms created the next year for Ontario and Quebec both included the maple leaf. Later the maple leaf appeared on coins. Between 1876 and 1901, it appeared on all Canadian coins. The modern one-cent piece has two maple leaves on a common twig(细枝)，a design that has gone almost unchanged since 1937.

    During the First World War, the maple leaf was included on the badge(徽章) of the Canadian Expeditionary Force. Since 1921, the Royal Arms of Canada have included three maple leaves as a special Canadian symbol. In 1939, at the time of World War Ⅱ, many Canadian troops used the maple leaf as a special sign.

    With the announcement of Canada's new flag in 1965, the maple leaf has become the Canadian symbol. On February 15 of that year, the red maple leaf flag first appeared as the National Flag of Canada.

    Snoring(打鼾) is noisy breathing during sleep. It is a common problem among all ages and it influences about 90 million American adults. People most at risk are males and those who are overweight, but snoring is a problem of both genders, although it is possible that women do not present this complaint as frequently as men.

    Snoring is often the loud or harsh sound that can occur as you sleep. You snore when the flow of air makes the tissue in the back of your throat vibrate(颤动) as you breathe. The sound most often occurs as you breathe in air, and can come through the nose, mouth or both two organs. It can occur during any stage of sleep.

    About half of people snore at some point in their lives. Snoring is more common among men, though many women snore. It appears to run in families and becomes more common as you get older. About 40 percent of adult men and 24 percent of adult women are habitual snorers. Men become less likely to snore after the age of 70.

    Sleeping on your back may make you more likely to snore. You may snore when your throat or tongue muscles are relaxed. And substances(物质) that can relax these muscles may cause you to snore. These include alcohol, muscle relaxants and other medicine.

    Snoring can be a nuisance to your partner and anyone else nearby. You may even snore loudly enough to wake yourself up. Though, in many cases people do not realize that they snore. Snoring can also cause you to have a dry mouth when you wake up.

    Light snoring may not disrupt your overall sleep quality. Heavy snoring may be connected with a risk factor in the heart disease, stroke and many other health problems. So never take it lightly.

    Generally speaking, waiting rooms are always filled with a lot of impatient people. However, a project carried out by The Observer suggests that people regard these spaces as a place of refuge (避难), a window in their tightly scheduled lives.

    Ella Doroudy, Margate Station

    We were at the beach for the day, and now are on our way home. We don't have to wait very long, because we checked the timetable so we got here in time for the train. I just chat with my mates, really, and listen to music until the train comes. Waiting with other people is easier because you can kill time when you're talking about stuff.

    Caroline Lacey, Streatham Dental Center

    I don't really get nervous about seeing the dentist, but since these two fillings (补牙的材料) came out I've been in sharp pain. It's very bright and airy here, so it's quite calming. Usually I kill time by reading magazines. I've been coming to the dentist as and when I need to, but now it's got to be regular.

    Katie Hawkins, Model Casting

    I was a bit late today, which I'm quite pleased about because some of these girls have been waiting ages. I can't help but look at everyone else a bit — I look at the other girls and think: "I wonder if they'll like her better than they like me." While I'm waiting, I'm thinking: "Oh come on. I do have a life!"

    Paul Thomas, Royal London Hospital

    I feel pretty indifferent (满不在乎的)  while I'm waiting here, to be honest. It's something I've got very used to since my motorbike accident seven years ago. I've had about 32 operations so far. It's no good rushing in thinking you're going to escape in five minutes, so I just sit back and people-watch, really.

    For many people, the Transformers movies are the greatest Hollywood blockbusters (大片). And among the Transformers themselves, the yellow Autobot named Bumblebee is certainly the favorite. He may be one of the smallest and weakest of the alien machines, but he is always loyal to his friends and shows great bravery in battle.

    In the new film, Bumblebee is found in a junkyard (废车场) and is full of honeybees. He always finds himself in awkward (尴尬的) situations, but people like his cute and naive looks. In addition to his blue eyes, Bumblebee's body language and movements are adorable. At one point, he sits with his legs straight out, with his huge feet making him look like a 5-year old trying on his dad's shoes.

    Bumblcbee is the Transformer who has the greatest affinity (亲和力) with humans. He starts journey with Watson, who is at a loss about her future and wants a friend. As a result of their adventure together. Watson grows up and starts to work toward her life goal of becoming a musician. As for Bumblebee, as we know, is a robot from outer space, he now has a better understanding of his task to protect the Earth. Every adventure has a beginning, as the movie poster puts it. More importantly, every adventure needs a good partner. The considerate, positive and warm Bumblebee is definitely a good choice according to US actress I Hailee Stcinfeld, who plays Watson in the film.