Mosquitoes have an extraordinary ability to find humans far away and fly straight to their skin. Mosquitoes can do more than cause an itchy (发痒的）wound. Some mosquitoes spread several serious diseases, including Dengue, yellow fever and malaria.

    Over one million people worldwide die from these diseases each year. New research now shows how mosquitoes choose who to bite.

    Mosquitoes need blood to survive. They are attracted to human skin and breath. They smell the carbon dioxide gas, which all mammals breathe out. This gas is the main way for mosquitoes to know that a warm-blooded creature is nearby.

    But mosquitoes also use their eyes and sense of touch. Michael Dickinson is a professor at the California Institute of Technology. His research shows how these small insects, with even smaller brains, use three senses to find a blood meal.

    Michael Dickinson's team used plumes—a material that rises into the air of carbon dioxide gas into a wind tunnel (隧道). They then used cameras to record the mosquitoes. The insects followed the plume.

    Then, the scientists placed dark objects on the lighter colored floor and walls of the tunnel. Mr. Dickinson said, at first, the mosquitoes showed no interest in the objects at all. “What was quite surprising is that the mosquitoes fly back and forth for hours. These are hungry females and they completely ignore the objects on the floor and wall of the tunnel. But the moment they get a hit of CO₂, they change their behavior quite obviously and now would become attracted to these little visual blobs (斑点).”

    This suggested to the researchers that a mosquito's sense of smell is more important in the search for food. Once mosquitoes catch a smell of a human or animal, they also follow visual signals.

    The English language has a lot of words which can be used in many different ways and in many different expressions.

    One such example is the word matter. In fact, matter can mean just about anything. It could be one of the most useful words in the English language.

    Let's get to the heart of the matter —a matter of principle(原则).

    If someone says that you owe(欠) him $50, but you don't, a friend might say, “Well, you could pay him the $50. It's not that much money. Then you won't have to hear him say it anymore. But if you do not owe him the money, do not pay him the money. It's a matter of principle.

    There is another way to use the word matter. But be careful with your choice of words.

    If you ask someone, “What's the matter?”, it shows you are worried about the other person. But saying, “What's the matter with you?” has a completely different meaning. And it usually sounds rude (粗鲁的). In fact, when you say, “What's the matter with you?” you are suggesting that the person did something wrong or stupid.

    Another expression that could sound rude is to say, “It doesn't matter to me.” Here, it depends on the context, and how you say it.

    Let's say you tell someone that a friend just got a big raise at work. That person answers with, “It doesn't matter to me.” Here, it means he or she does not care. And it sounds rude.

    But saying, “Oh, you pick where we eat dinner. It doesn't matter to me.” does not sound rude. In this situation, “it doesn't matter” shows you are easy-going(随和的).

    No matter how you look at it and what you say, matter is a very useful word. And it's only a matter of time before you will become an expert on the use of matter.

    Benito Juarez, a poor Indian boy, was twelve years old when he left his village home in December 1818.Benito walked forty-one miles to the city of Oaxaca, high in the mountains of Mexico. When he heard the Spanish spoken by the city people, Benito didn't know what they were saying.

    First, Benito became a servant for a wealthy gentleman, Serer Maza. Soon, he went to work for Antonio Salanueva ,a church(教会)librarian. Antonio repaired and copied the library books, keeping them in good shape.  Benito became his helper and his housekeeper. Antonio loved to teach. Benito soon became his student as well as his servant. With the help of Antonio, Benito learned to speak, read, and write Spanish.

    At that time in Mexico, many people believed that Indians were not smart enough to read or learn. Antonio knew that was not true. Indians had been prevented from learning by a lack of schools. The first Spanish missionaries(传教士)who came to Mexico had educated the native people. In fact, churches from Spain had built the first college on the North American continent(大陆)for the Indians. As more Spanish came to Mexico, however, the Indian children were crowded out of the schools.

    Benito was a good and bright student, so Antonio developed a plan for him. In 1821, when Benito was fifteen, Antonio decided to enroll him in a school for boys. Antonio taught Benito what he needed to pass the entrance test for the school.

Benito became a student at the college. His studies were difficult, and he was teased because he was the only Indian student there. He succeeded in spite of these challenges. Later, as the laws changed, Benito was able to attend a public college with other Indians.

    Benito Juarez continued his education and became a lawyer and, much later, the President of Mexico from 1861 to 1872. He led the Mexican people to victory over the French, who tried to rule Mexico, and fought for the rights of Indians. He is one of the great heroes in Mexican history.

    The San Diego Center for Children recently added three acres of land to its 9-acre Linda Vista campus. Thanks to the efforts of Assembly member Dr. Shirley Weber, the state sold the land near the Center's main campus. Now the Center, which is the oldest children's nonprofit (非营利的机构) in the region, will be able to provide more treatment and educational foster care (看护) to kids and families who need it most.

    Jewish Family Service of San Diego (JFS) received a $10, 000 grant from the USS Midway Foundation to support its Hand Up Food Pantry (食品贮藏室). "Jewish Family Service works every day to help struggling families and individuals in San Diego move forward and build more stable, secure lives," says JFS CEO Michael Hopkins.

    St. Madeleine Sophie's Center raised more than $16, 000 at its Swing with Santa Golf Tournament (锦标赛). The funds will go toward programs for adults with developmental disabilities. The 5th annual tournament included 18 hotels, food and drinks, and two celebrity appearances: both Santa and Elvis made a dramatic entrance via helicopter.

    Coming Up: Raise money for the 4SRanch-Del Sur Community Foundation and Helen's Closet (壁橱，衣帽间) at the 9th Annual Thank You Run on Thanksgiving Day, November 22. Helen's Closet serves patients with ALS. The distance is 5K with a 1K Fun Run for children aged 8 and under.

    Chester is one of the best cities in the UK. As soon as you arrive in Chester you will appreciate the city's unique atmosphere and sense of history. Founded by the Romans over 2,000 years ago, much of the Roman influence remains and Chester's city walls are the most complete in Britain. Combined with history and heritage(遗产), Chester is a dynamic city full of bars, pubs, clubs, hotels and restaurants for you to discover, tempting you to visit again and again.

    Travelling to Chester?

    Chester is easily accessible by many means of transport — whether you are travelling by rail, car, bus or plane. Please check our route planner below to help you plan your journey to Chester. Once you arrive in the city there are numerous car parks; however, during rush hours the easiest way to travel in Chester city centre is via park and ride facilities, which are parking lots with public transportation.

    Hotels?

    From bed & breakfasts to the luxury of Chester's only five star hotel, Chester has all covered. Whether your trip is for business or pleasure your room is just a click away!

    Sightseeing and Tours?

    One of the best ways to see Chester is by a guided tour and you have a variety to choose from. Whether you choose the traditional guided walk, to be guided around Chester's historical landmarks by bus or to take a boat down the River Dee, you will sure enjoy the delights of Chester.

    For many of us, summertime means road trips to the beach or mountains, or at the very least some additional dust and bird poop on the exterior of our vehicles. The extra dirt leads us to do one of two things: wash our car in the driveway or head to the car wash. But which choice is better for the environment?

    The main concerns with either choice are the amount of fresh water being used and the types of chemicals used to remove the dirt. Both of these concerns can be closely monitored when washing the car at home, says Katy Gresh, spokeswoman for the Southwest Region of the Pennsylvania Department of Environmental Protection. She advises car owners to put aside a set amount of water for the entire wash. "It's just like brushing your teeth," she says, "You don't want to leave the water running of more than you need for the job." But even following this advice comes with an environmental risk: Washing your car in the driveway or street flushes the dirty water into storm drains.

    John Schombert, executive director of 3 Rivers Wet Weather, his organization works to educate the public about storm sewers (下水道) and water runoff, keeping this untreated water from entering the Allegheny region's waterways. "We ask people to, consider washing their cars on lawns or other permeable (透水的) surfaces where the water gets absorbed," Schombert says. "Soil can break down and help filter (过滤) those things," Schombert says. "Storm sewers are not made for waste disposal." Even when car owners use natural soaps to wash their cars, which Schombert says are probably ineffective at breaking down grease anyway.

    The commercial car wash down the street knows full well the rules regarding wastewater in storm sewers. According to the International Carwash Association (ICA), professional car washes must use water reclamation systems. These mandated processes not only keep the dirty water out of storm sewers and regular water treatment systems, but they also work to reduce water usage at commercial facilities.