下列关于流感病毒的描述，不正确的是（）
A.流感病毒为单负链RNA病毒
B.根据糖蛋白HA和NA抗原性不同，可分为甲、乙、丙三型
C.病毒抗原检测具有快速和灵敏度高的优点，有助于早期诊断
D.血凝抑制试验或补体结合试验可以检测急性期和恢复期患者血清总抗体，效价4倍升高有助于回顾性诊断和流行病学调查，但不能用于早期诊断
E.目前发现的高致病性禽流感亚型多为H5或H7血清型
参考答案：B
解析：流感病毒为单负链RNA病毒，根据核蛋白抗原性的不同，可分为甲、乙、丙三型。病毒抗原检测具有快速和灵敏度高的优点，有助于早期诊断。血凝抑制试验或补体结合试验可以检测急性期和恢复期患者血清总抗体，效价4倍升高有助于回顾性诊断和流行病学调查，但不能用于早期诊断。目前发现的高致病性禽流感亚型多为H5或H7血清型。
Is there something that you’ve always wanted to try but just never had the time? Well, make plans to try it now since you are on summer vacation．Not all vacations call for taking a tour bus to take photos of famous landmarks. Some vacations allow you plenty of opportunities to learn. The most difficult aspect of a learning vacation vacation may be choosing one because the possibilities are endless．If you enjoy cooking, various companies can take you to Italy, France, Spain, Mexico or even Peru. Once there, you can learn to prepare the local cuisine（烹饪）. Trips are often planned to fit in with local food festivals or special events. The term “learning vacation” often brings language to mind. The best way to learn a language is in an environment where it’s spoken. Study Spanish, French or English. Or attempt a more unusual language like Polish, Estonian or Thai. You’ll be able to learn about the country and absorb the culture at the same time. If you are fond of sports, you can polish your skills or learn new ones. Golf and tennis schools welcome players of all levels. If you want a bigger thrill, you can learn to surf, go climbing or race cars. It’s even possible to learn the art and techniques of bull fighting while on vacation! You can also discover our inner artist. Many places offer painting classes in different mediums. The scenic locations of the schools offer plenty of subjects that provide inspiration for practice. If you prefer capturing the world on film, take a photography vacation. Travel with a small group to photograph beautiful animals or scenery. You can also practise your technique on people or at historical sights. Once you decide on a vacation, choose a company carefully. Request names of recent customers you can contact, and then ask them for an evaluation. The more you know before you go, the better prepared you’ll be. Then go out and learn something! 56．Why is it hard for you to decide on a learning vacation? A．Because it is hard for you to make plans. B．Because the possibilities are unlimited. C．Because there are many good foods from abroad. D．Because there’re too many food festivals or events. 57．The advantages of learning a language in its native country is that . A．the environment is fit for you to use the language B．you are able to learn the original foreign language C．native speakers offer you a lot of chances to practise D．you can learn the language and experience its culture 58．Which of the following sports suit you if you don’t like thrills? A．Car racing. B．Playing tennis. C．Rock climb. D．Surfing. 59．The structure of the text would be .
60．The purpose of writing the text is to . A．advertise some popular summer programmes B．encourage readers to have a good time relaxing C．offer some tips on how to enjoy a learning vacation D．attract more readers to spend summer time learning |
