Barbara McClintock was one of the most important scientists of the twentieth century. She made important discoveries about genes（基因）and chromosomes（染色体）.

    Barbara McClintock was born in 1902 in Hartford, Connecticut. Her family moved to the Brooklyn area of New York City in 1908. Barbara was an active child with interests in sports and music. She also developed an interest in science.

    She studied science at Cornell University in Ithaca, New York. Barbara was among a small number of undergraduate students to receive training in genetics in 1921. Years later, she noted that few college students wanted to study genetics.

    Barbara McClintock decided to study botany, the scientific study of plants, at Cornell University. She completed her undergraduate studies in 1923. McClintock decided to continue her education at Cornell. She completed a master's degree in 1925. Two years later, she finished all her requirements for a doctorate degree.

    McClintock stayed at Cornell after she completed her education. She taught students botany. The 1930s was not a good time to be a young scientist in the United States. The country was in the middle of the great economic Depression. Millions of Americans were unemployed. Male scientists were offered jobs. But female geneticists were not much in demand.

    An old friend from Cornell, Marcus Rhoades, invited McClintock to spend the summer of 1941 working at the Cold Spring Harbor Laboratory. It is a research center on Long Island, near New York City. McClintock started a temporary（临时的）job with the genetics department. A short time later, she accepted a permanent（永久的）position in the laboratory. This gave her the freedom to continue her research without having to teach or repeatedly ask for financial aid.

    By the 1970s, her discoveries had had an effect on everything from genetic engineering to cancer research. McClintock won the Nobel Prize for Physiology or Medicine in 1983 for her discovery of the ability of genes to change positions on chromosomes. She was the first American woman to win an unshared Nobel Prize.

    Homeless people face a lot of challenges, - such as not having enough to eat and no job opportunities. Some of the most basic challenges, - however, -are not having clean water and toiletries (卫生用品)-a big problem for homeless teens. That encouraged a young researcher to invent a multi-purpose product to help these teens.

    "I was born into a life of volunteering," said 13-year-old Leia Gluckman. And that's true. Her mom is a president of an organization providing help for homeless teens. Leia and her brother have volunteered there for years. When she was a young girl, Leia helped serve food where teens were eating. Now she's a teenager herself, and she's managing the toiletry and clothing work there.

    From her work at the center, Leia noticed that teens asked for some toiletries more than others. What they needed most often were toothpaste, body powder (粉)and shampoo(洗发水).Leia wondered whether she could create a product to serve all three purposes.

    It would need to take away dirt and oil from skin and hair. It would need to clean teeth. Also, it would need to kill bacteria (病菌)without being harmful to people. She wanted her ingredients (产品成分)to be natural, to be able to break down easily and to taste and smell pleasant. Moreover, this product had to be low﹣cost and have a long shelf life.

    Leia started by going to stores and looking at the ingredient lists for toiletries. Then she tried eight different ways. She tested each way to see how well it worked.

    Not all of them worked well. But she finally decided on three. Each includes salt and baking powder. Salt helps clean teeth and skin; baking powder helps take in bad smells. She also has some other recipes which include some special materials that give her products different tastes and smells, which would let teens choose a product based on personal preferences.

    It wasn't easy, but Leia came up with some model products. She presented them at the finals of Broadcom MASTERS science competition.

    Leia wants to develop her products further. "Could it possibly be used to drive away mosquitoes (蚊子)?" she wonders.

    "Science offers a way to go about solving problems and helping people," says Leia. And she thinks her products could benefit a great number of people, not just the homeless. Anyone in an area with little or no chance to get clean water could find her products useful, maybe refugees (难民) and soldiers who are sent to places without running water.

    Our monthly talks start at 19: 30 on the first Thursday of each month except August. Admission is at normal charges and you don't need to book. They end around 21: 00.

    November 7th The Canal(运河)Pioneers(先驱者), by Chris Lewis. James Brindley is recognized as one of the leading early canal engineers. He was also a major player in training others in the art of canal planning and building. Chris Lewis will explain how Brindley made such a positive contribution to the education of that group of early "civil engineers".

    December 5th Ice for the Metropolis, by Malcolm Tucker. Well before the arrival of freezers, there was a demand for ice for food preservation and catering.

    Malcolm will explain the history of importing natural ice and the technology of building ice wells, and how London's ice trade grew.

    February 6th An Update on the Cotswold Canals, by Liz Payne. The Stroud water Canal is moving towards reopening. The Thames and Severn Canal will take a little longer. We will have a report on the present state of play.

    March 6th Eyots and Aits—Thames Istands, by Miranda Vickers. The Thames had many islands. Miranda has undertaken a review of all of them. She will tell us about those of greatest interest.

Few parents can hear the words "What can I do to help?" from their kids. Teenagers spend more time on video games, computers and mobile phones, so they help less with housework.

Students at a primary school in Fuzhou, East China's Fujian Province were required to clean the school toilets to help them develop good habits. But some parents are strongly against the idea. They can't see the advantages of students doing such chores. They think that the school should provide students with a proper education, not the chance to be school cleaners.

In fact, parents, schools and society play an equally (同等地) important role in developing the character of students. It is good for schools to give students such tasks, because few of the students will do them at home. Their parents want them to do homework only.

In recent years, some parents will make mountains out of molehills when students are asked to do some chores in schools. Some will complain the teachers if their kids get hurt in schools; some will even challenge the schools' teaching methods and management. As a result, many primary schools, especially those in big cities, do not let students join in outdoor activities during breaks, fearing that they might get hurt. This is bad for the development of students' best qualities.

What the primary school in Fuzhou doing is worth praising. Doing chores can put a sense of responsibility (责任感) into students' minds and teach them the spirit of rules as well as teamwork. Also, it can make students' in-school experiences more meaningful.