一次函数$y=ax+b$，当$x>\frac{2}{3}$时，$y>0$，那么不等式$ax+b\ge 0$的解集为（　　　）

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      为响应***5月13日主持召开国务院常务会议时提出的确定加快建设高速宽带网络促进提速降费的措施，助力创业创新和民生改善的会议精神，中国移动、中国联通、中国电信于5月16日分别公布各自提速降费方案。但令人始料不及的是，号称史上最大提速降费的方案却遭到了大多数网友的吐槽，觉得自己又被忽悠了一次，很多网友都认为得到的实惠并不多。新浪网调查显示，10.95万名受访网友中，84.9%的人认为运营商没诚意，降价方案在玩文字游戏。例如对于“夜间流量”，网友吐槽：谁大半夜上网？

       中国移动推出了以下方案：①推出新的优惠流量包；②套餐外流量费用降低；③国际及港澳台漫游流量资费降低；④推出话音短信不限量套餐；⑤更多城市将享受流量不清零、流量交易、流量共享等服务；⑥中国移动还承诺到2015年底流量综合资费同比将下降35%以上。中国电信推出的方案是：①流量优惠。天翼4G套餐流量单价下降50%；②流量加装包“买一送一”活动；③定向流量。视频、淘宝套餐可获赠流量；④宽带提速降费；⑤开展“百城百兆大提速”活动，主推百兆宽带。中国联通则推出了以下方案：①流量优惠。10元包1.5GB省内流量半年包；②定向流量。视频定向流量包，最优惠流量包价格每月18元6GB；③推出流量银行平台，可进行流量转赠、分享、兑换等功能；④宽带资费降价。

康德说：“我们的时代是一个批判的时代，一切事物都必须接受审判”。这里“批判”的本意是强调(　　)

    A great invention by an 18-year-old high school student grew out of a simple problem most teenagers meet with.

    “I'm a teenager and I have a cellphone and my cellphone battery always dies，so I was really looking for a way to improve energy storage，” Eesha Khare said on Tuesday. “That's how I came across the super capacitor.”

    The teenager who came from California, and graduated from high school last week，won a $50，000 prize on May 17，2013 at the Intel International Science and Engineering Fair for creating a device that can store enough energy to charge a cellphone in 20 to 30 seconds.

    “It charges very quickly and can store a lot of energy，” Khare said. “The cool thing is that it's a lot thinner than one strand of hair.”

    Khare hasn't used her invention to recharge a cellphone yet，but she used it to power a light-emitting diode (LED) in order to show its capability(容量). If used on cellphones，the supercharger would slide on to the phone's battery to juice it up in a matter of seconds. The technology isn't available to consumers yet，and it could be years until it is.

    At an Intel event in Phoenix，Khare won the Intel Foundation Young Scientist Award，taking second place overall in the world's largest high school science research competition. She beat out more than 1，600 finalists from 70 countries. She said that she has been approached by several companies to continue her research，but she is now focused on attending Harvard University in autumn.

    “Right now，just my education，but hopefully we'll see what happens in the future，” she said about her plans. “I have a lot of interests，so we'll see what I do in the future.”

①高温下用过量的碳还原二氧化硅制得粗硅，同时得到一种可燃性气体；

②粗硅与干燥的HCl气体反应制得SiHCl₃（Si+3HCl $\underset{铜粉}{\overset{250\text{-}300^{\circ }C}{=}}$ SiHCl₃+H₂）；

③SiHCl₃与过量的H₂在1 100～1 200℃的温度下反应制得纯硅，已知SiHCl₃能与水剧烈反应，在空气中易自燃．

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