单选题能识别mRNA中的密码子5ˊ-GCA-3ˊ的反密码子为

单选题A．白喉B．淋巴结结核C．急性蜂窝织性阑尾炎D．乙型肝炎

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单选题飞机上升和下降时，乘务员嘱乘客作吞咽动作，其意义在于

单选题下列有关风湿病病变性质的描述，哪项是恰当的

单选题与DNA修复调节基因突变相关的肿瘤是

单选题分泌降钙素的甲状腺癌是

单选题能代表肽链合成起始信号的遗传密码为

单选题No doll outshines Barbie's celebrity. If all the Barbies and her family members-Skipper, Francie and the rest-sold since 1959 were placed head to toe, they would circle the Earth more than seven times. And sales are sure to boom in 2009, when the fashion doll celebrates her 50th birthday on March 9th. Barbie will star at an array of global events honouring her milestone, possibly including a glitzy affair at New York's Fashion Week in February (most of the world's top fashion designers, from Givenchy to Alexander McQueen, have designed haute couture for her). On her birthday, Mattel, the company that makes her, will launch a souvenir doll honouring the original Barbie in her black-and-white striped swimsuit and perfect ponytail. It will be available for purchase only that one day. Another Golden Anniversary doll targets collectors. Barbie fans have planned hundreds of events, including the National Barbie Doll Collectors Convention in Washington, DC, which is already sold out. When Ruth Handler created Barbie in 1959, a post-war culture and economy thrived but girls still played with baby dolls. These toys limited the imagination; so Handler introduced Barbie the Teen-Age Fashion Model, named after her daughter, Barbara. Jackie Kennedy soon sashayed onto the world stage and Barbie already had a wardrobe fit for a first lady. Barbie bestowed on girls the opportunity to dream beyond suburbia, even if Ken at times tagged along. Barbie entranced Europe in 1961 and now sells in 150 countries. Every second three Barbies are sold around the world. Her careers are myriad-model, astronaut, Olympic swimmer, palaeontologist and rock star, along with 100 others, including president. Like any political candidate, controversy hit Barbie in 1992 when Teen Talk Barbie said "Math class is tough" and girls' education became a national issue. She has been banned (in Saudi Arabia), tortured (by pre-teen girls, according to researchers at the University of Bath's School of Management) and fattened (in 1997). Feminists continue to bash Barbie, claiming that her beauty and curves treat women as objects. But others see her as a pioneer trendsetter, crashing the glass ceiling long before Hillary Clinton cracked it. High-tech entertainment now attracts girls and Barbie also faces fierce competition from various copycats including the edgier, but less glare, Bratz dolls. The Bratz suffered a setback in 2008．Mattel sued MGA Entertainment, Bratz's producer, for copyright infringement. A judge awarded Mattel $100 million in damages. Mattel has smartly ensured that Barbie products reflect current trends. Through two Barbie websites, girls can design clothes, network and play games. The pink Barbie brand is licensed for products from DVDs and MP3 players to bicycles and even 24-carat gold and crystal jewellery. Barbie collectors fuel an entire global industry on eBay and at conventions. To entice collectors, Mattel regularly releases pricey limited-edition dolls based on characters in films and popular culture. Industry analysts believe Barbie will remain a bestselling and lasting icon regardless of competition. "Barbie's been out in the world and had fun, and she's ready for her second career," says Rachel Weingarten, a pop culture expert. "I don't see her adopting five children from five different countries, but I could see Barbie with a conscience, activist Barbie. " At 50 Barbie will also be a marvel of plastic surgery and eternal youth. And she still knows how to party.

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单选题不属于肾分泌的物质是

单选题下列属于代偿性肥大的是

单选题A．引起特定感觉并激发大脑皮层发放传出冲动B．协调各种感觉在大脑皮层与皮层下结构之间的联系C．维持和改变大脑皮层的兴奋状态和维持觉醒状态D．维持睡眠状态E．参与学习和记忆

单选题以变质为主的炎症性疾病是

单选题伤寒病的潜伏期中，伤寒杆菌寄生、繁殖的细胞是

单选题在下列选项中，符合IgA肾病镜下特征的病变是

单选题绝大多数能治愈的肾小球肾炎是

单选题下列选项中属于生理性钙化的是

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