[单项选择]流行性感冒大流行是由于流感病毒抗原性变异，形成什么而引起的（）
A. 血凝素，抗原性漂移
B. 神经氨酸酶，抗原性漂移
C. 血凝素和神经氨酸酶抗原性转换
D. 血凝素和神经氨酸酶抗原性漂移
E. 血凝素和NP蛋白，抗原性转换

[多选题]按照《安全生产法》的规定，必须进行安全条件认证和安全评价的项目有哪些？
A.矿山建设项目
B.建筑工程建筑项目
C.用于生产、存储危险品的建设项目
D.总投资超过1亿元的项目
E.起重机械的设计与制造

[单选题]参加重大灭火救援作战行动，或者开展攀登、水域救援、实战模拟等高风险科目训练，或者执行其他危险性任务时，应当预先进行（）。
A. 安全预测
B.安全风险评估
C.伤情评估
D.灾害评估

[判断题]如施工单位作业期间提出监护要求，电力设施产权单位应及时安排工作人员进行作业现场安全监护，督促施工单位执行安全作业措施。
A.正确
B.错误

[单项选择]

Uncle Sam is a tall, thin man. He’s an older man with white hair and a white beard. He often wears a tall hat, a bow tie, and the stars and stripes of the American flag.
Who is this strange-looking man Would you believe that Uncle Sam is the US government But why do you call the US government Uncle Sam
During the War of 1812, the US government hired meat packers to provide meat to the army. One of these meat packers was a man named Samuel Wilson. Samuel was a friendly and fair man. Everyone liked him and called him Uncle Sam.
Sam Wilson stamped the boxes of meat for the army with a large US for United States. Some government inspectors came to look over Sam’s company.
They asked a worker what the US on the boxes stood for. As a joke, the worker answered that these letter stood for the name of his boss, Uncle Sam.
The joke spread, and soldiers began saying that their food came from Uncle Sam. Before long, people called all things
A. dark hair
B. a bow tie
C. a box
D. a shirt

[单选题]我国社会主义改造提前完成,开始进入社会主义初级阶段的时间是( )。
A.1956年春
B.1956年夏
C.1956年秋
D.1956年底

[单项选择]Why do we invest so much hope in new technology and why are we so disappointed when the Next Big Thing turns out to be just a new computer This is what I’m asking myself after Apple’s (62) over hyped product introduction. This time around the Next Big Thing is called an iPad. It’s (63) an oversize iPod Touch, and it will be great for watching movies, reading books, and browsing the Web.
(64) for some of us who sat in the audience watching Steve Jobs introduce the device, the whole thing felt like a (65) . The iPad is a perfectly good product. It’s reasonably (66) , and after spending a few minutes with one, I’m pretty sure I’ll buy one for myself and probably (67) second one for my kids to watch movies on road trips.
Then why are we so (68) The case is that at the very (69) , we had hoped a tablet from Apple would do something new. Jobs and his (70) kept using words like "breakthrough" and "magical", but the iPad is (71
A. behavior
B. invention
C. fantasy
D. act