已知-3x2+14x+c≥0的解为，则c=______。 A．3 B．-3 C． D．-5 E．5

某公司员工义务献血，在体检合格的人中，O型血的有10人，A型血的有5人，B型血的有8人

已知(m+n)2=10，(m-n)2=2，求m4+n4=______．

如图所示，AB是⊙O的直径，CD是弦，若AB=10，CD=8，那么A

设ax3+bx2+cx+d能被x2+h2(h≠0)整除，则a，b，c，d之间的关系为______．

A.条件(1)充分，但条件(2)不充分．B.条件(2)充分，但条件(1)不充分．C.条件(1)和(2)单独都不充分，但条件(1)和(2)联合起来充分．D.条件(1)充分

某种产品按质量分为10个档次，若生产最低档次产品，每件可获利润8元，每提高一个档次

若等比数列{an}的前n项和Sn=4n-1+a，则a的值为______． A．-4 B．4 C．0 D． E．

The power and ambition of the giants of the digital economy is astonishing—Amazon has just announced the purchase of the up market grocery chain Whole Foods for $13.5bn, but two years ago Facebook paid even more than that to acquire the WhatsApp messaging service, which does not have any physical produce at all. What WhatsApp offered Facebook was an intricate and finely detailed web of its users' friendships and social lives. Facebook promised the European commission then that it would not link phone numbers to Facebook identities, but it broke the promise almost as soon as the deal went through. Even without knowing that was in the messages, the knowledge of who sent them and to whom was enormously revealing and still could be. What political journalist, what party whip, would not want to know the makeup of the WhatsApp groups in which Theresa May's enemies are currently plotting? It may be that the value of the Whole Foods to Amazon is not so much the 460 shops it owns, but the records of which customers have purchased what. Competition law appears to be the only way to address these imbalances of power. But it is clumsy. For one thing, it is very slow compared to the pace of change within the digital economy. By the time a problem has been addressed and remedied it may have vanished in the marketplace, to be replaced by new abuses of power. But there is a deeper conceptual problem, too. Competition law as presently interpreted deals with financial disadvantage to consumers and this is not obvious when the users of these services don't pay for them. The users of the services are not their customers. That would be the people who buy advertising from them—and Facebook and Google, the two virtual giants, dominate digital advertising to the disadvantage of all other media and entertainment companies. The produce they are selling is data, and we, the users, convert our lives to data for the benefits of the digital giants. Just as some ants farm the bugs called aphids for the honeydew they produce when they feed, so Google farms us for the data that our digital lives yield. Ants keep predatory insects away from where their aphids feed; Gmail keeps the spammers out of our inboxes. It doesn't feel like a human or democratic relationship, even if both sides benefit. According to Paragraph 1, Facebook acquired WhatsApp for its ______.

已知(x＞0，y＞0)，则 A．-1 B． C． D． E．

鸡与兔共100只，鸡的脚数比兔的脚数少28，则鸡与兔各有______只。

从2只相同的红球，2只相同的黑球中任选2只，放入2个不同的盒中，放法种数总共有

设等差数列{an}的公差d≠0，a1=9d，若ak是a1和a2k的等比中项，则k=______。

动物园售票处规定，一人券2元一张，团体券15元一张(最多可供10人参观)，六年级一班有58人

如图所示，在直角三角形ABC中，∠C=90°，AF=FE=ED=DC=CB，则∠A= A． B． C． D． E．

完成某项任务，甲单独做需要4天，乙单独做需要6天，丙单独做需要8天。现甲、乙、丙三人依次一日一轮换地工作，则完成该项任务需要 A． B． C．6天 D． E．4天

如图所示，已知M是平行四边形ABCD的AB边的中点，CM交BD于点E，则图中阴影部分面积与四边形ABCD面积之比为______． A． B． C． D． E．

满足x1+x2+x3+x4=12的正整数解的组数有______组．

自信 论说文：根据下述材料，写一篇700字左右的论说文，题目自拟。 有人说：“人，必须要有自信。” 有人反驳道：“没有实力，哪来的自信?”

论说文：根据下述材料，写一篇700字左右的论说文，题目自拟。 大豆是蛋白质含量极其丰富而又十分廉价的食物，可它的境遇曾一度尴尬，煮熟的大豆难引起人们的食欲