下图表示“粮桑渔畜”农业生态系统的基本模式。据图示判断,下列说法正确的是( )
A.农田生态系统中,除草、治虫可以提高其抵抗力稳定性
B.利用苏云金芽孢杆菌的毒蛋白基因培育抗虫作物,是利用了生物多样性的间接价值
C.饲养家禽时,可以适当延长光照时间来提高产蛋率,这是利用了物理信息的作用
D.该生态农业有效地促进了生态系统物质循环,提高了能量传递效率
有一种灌浆机可以将某种涂料以速度v持续喷在墙壁上,假设涂料打在墙壁上后便完全附着在墙壁上,涂料的密度为ρ,若涂料产生的压强为p,不计涂料重力的作用,则墙壁上涂料厚度增加的速度u为( )
A. B.
C. D.
| 计算单位 | 计划 | 最终完成 | 比计划增长% |
拖拉机 | 标准台 | 5146 | 12000 | 133.2 |
机耕面积 | 万亩 | 758 | 2754 | 263.3 |
据表可以推知
A. 国家工业布局均衡
B. 农业机械化与合作化相互促进
C. 国民经济迅速恢复
D. 生产领域出现明显的冒进现象
Since App Store was set up, it has been selling consumers one simple thing choice. Whether you wanted to play games, read the news, or do a thousand other things, there was something for whatever you desired.
Then something funny happened. Logging into the App Store today is like going into a shopping mall with only a coupon(优惠券) for one thing: There's so much choice; it might be easier to give up than to choose.
It isn't consumers who are burdened, though. Too much content of all kinds also has economic effects. When countless choices are available, it causes pressure, pushing prices down and driving us a bit crazy.
So what is the way forward? It may well be to turn less choice itself to the marketing strategy. There are already signs that this is happening. Firstly content companies are looking to prevent their offerings from getting lost in the tons of stuff. Most obvious is Disney, which is planning to open its own streaming service next year. The point is to narrow the focus so that those seeking Disney cartoons will have one place to go, rather than being around various services.
Yet if that represents a careful first step, there are more extreme options too. Consider the idea of a wine club: from tens of thousands of bottles each year, subscribers pay someone to select the most interesting ones. Perhaps what comes next for digital content is similar﹣carefully selected offerings from trusted sources that put choices in the hands of someone else in order to get rid of the anxiety of choosing.
Up to now, too much choice in digital media has only one solution: the algorithm(运算法则). But we' ve seen the trouble with algorithms on You Tube They feed you only what you've already said you like, not things you may not know you re into. Worse, they have a tendency to serve up disturbing content. The way forward can’t simply be more or better algorithms.
Instead, it's time for digital companies to start thinking about how to put limits on things: on how much we can use a device, or what we are available to choose from.
As we move further into the digital revolution, what people ask for is clear: Less.
1.What will too much choice of content on the market result in?
A.The shutdown of companies B.The anxiety of consumers
C.The poor quality of products D.The slowdown of economy
2.Which of the following statements is TRUE according to Paragraphs 4 and 5?
A.Content companies should withdraw their offerings online
B.Content companies should post their offerings on App Store
C.Content companies adopt different methods to narrow the consumers focus
D.Content companies open their own streaming services on You Tube
3.How do algorithms probably respond to consumers needs?
A.They make a better choice for them B.They help to remove disturbing content
C.They change their interest in digital media D.They fail to offer what they possibly like
4.What is the authors attitude towards limiting the choice consumers have ____.
A.Approving. B.Skeptical C.Opposing. D.Neutral
下列表示物质结构的化学用语或模型图正确的是
A.在潮湿的中性环境中,钢铁吸氧腐蚀的负极反应为:Fe-3e-=Fe3+
B.Cl−的结构示意图:
C.硅酸盐Ca2Mg5Si8O22(OH)2可用氧化物形式表示为:2CaO•5MgO·8SiO2•H2O
D.氯化镁的电子式: