题目内容
男性，28岁，咳嗽、咳黄白色痰。查体：T 38℃，P 88次/分，R 22次/分，BP 150/95mmHg，两肺底湿啰音，胸骨左缘第2肋间连续机器样杂音。胸片示主动脉弓突出，肺动脉圆锥隆出，考虑( )
查看答案
搜索结果不匹配？点我反馈
更多问题
下列哪种细菌为革兰阴性菌( )
科学家发现，一种名为“SK3”的蛋白质在不同年龄的实验鼠脑部的含量与其记忆能力密切相关：老年实验鼠脑部SK3蛋白质的含量较高，年轻实验鼠含量较少：而老年实验鼠的记忆力比年轻实验鼠差。因此，科学家认为，脑部SK3蛋白质含量增加会导致实验鼠记忆力衰退。以下哪项如果为真，最能支持科学家的结论在年轻的实验鼠中，也发现脑部SK3蛋白质含量较高的情况。已经发现人类的脑部也含有SK3蛋白质。 当科学家设法降低老年实验鼠脑部SK3蛋白质的含量后，它们的记忆力出现了好转。科学家已经弄清了SK3蛋白质的分子结构。
案例分析题Electronic mail has become an extremely important and popular means of communication.The convenience and efficiency of electronic mail are threatened by the extremely rapid growth in the volume of unsolicited commercial electronic mail. Unsolicited commercial electronic mail is currently estimated to account for over half of all electronic mall traffic, up from an estimated 7 percent in 2001, and the volume continues to rise. Most of these messages are fraudulent or deceptive in one or more respects.The receipt of unsolicited commercial electronic mail may result in costs to recipients who cannot refuse to accept such mail and who incur costs for the storage of such mail, or for the time spent accessing, reviewing, and discarding such mail, or for both. The receipt of a large number of unwanted messages also decreases the convenience of electronic mall and creates a risk that wanted electronic mail messages, both commercial and noncommercial, will be lost, overlooked, or discarded amidst the larger volume of unwanted messages, thus reducing the reliability and usefulness of electronic mail to the recipient. Some commercial electronic mail contains material that many recipients may consider vulgar or pornographic in nature.The growth in unsolicited commercial electronic mail imposes significant monetary costs on providers of Internet access services, businesses, and educational and nonprofit institutions that carry and receive such mail, as there is a finite volume of mail that such providers, businesses, and institutions can handle without further investment in infrastructure. Many senders of unsolicited commercial electronic mail purposefully disguise the source of such mall.Many senders of unsolicited commercial electronic mall purposefully include misleading information in the messages’ subject lines in order to induce the recipients to view the messages. While some senders of commercial electronic mail messages provide simple and reliable ways for recipients to reject (or ’opt-out’ of) receipt of commercial electronic mall from such senders in the future, other senders provide no such ’opt-out’ mechanism, or refuse to honor the requests of recipients not to receive electronic mail from such senders in the future, or both.Many senders of bulk unsolicited commercial electronic mail use computer programs to gather large numbers of electronic mail addresses on an automated basis from Internet websites or online services where users must post their addresses in order to make full use of the website or service.The problems associated with the rapid growth and abuse of unsolicited commercial electronic mall cannot be solved by the government alone. The development and adoption of techno-logical approaches and the pursuit of cooperative efforts with other countries will be necessary as well. The unwanted e-mail problem can be solved if （）.
案例分析题Natural flavorings and fragrances are often costly and limited in supply. For example, the vital ingredient in a rose fragrance is extracted from natural rose oil at a cost of thousands of dollars a pound; an identical synthetic substance can be made for 1% of this cost. Since the early twentieth century, success in reproducing these substances has created a new industry that today produces hundreds of artificial flavors and fragrances. Some natural fragrances are easily synthesized; these include vanillin, the aromatic ingredient in vanilla, and benzaldehyde, the aromatic ingredient in wild cherries. Other fragrances, however, have dozens, even hundreds of components. Only recently has it been possible to separate and identit3, these ingredients by the use of gas chromatography and spectroscopy. Once the chemical identity is known, it is often possible to synthesize them. Nevertheless, some complex substances, such as the aroma of fresh coffee, have still not been duplicated satisfactorily. Many of the chemical compounds making up these synthetics are identical to those found in nature, and are as harmless or harmful as the natural substances. New products must be tested for safety, and when used in food, must be approved by the U.S. Food and Drug Administration. The availability of synthetic flavors and fragrances has made possible a large variety of products, from inexpensive beverages to perfumed soap to used cars with applied "new car odor." Which of the following is NOT true according to the last paragraph（）
微信支付 
支付宝支付