问题 解答题
某公司甲、乙两仓库内分别存有电泵80台和70台,现需要将库存的电泵调往A厂100台和B厂50台,已知从甲、乙两仓库运送电泵到A、B两厂的运费(元/台)如下表:
厂名运费(元/台)
甲仓库乙仓库
A厂1420
B厂108
(1)设从甲仓库运送到A厂的电泵为x台,求总运费y(元)与x(台)之间的函数关系式,并写出x的取值范围;
(2)若总运费不超过1936元,则有几种不同的调运方案(只需写出几种方案即可),并说明此时哪一种方案运费最低及最低时的调运方案.
答案

(1)y=14x+10(80-x)+20(100-x)+8(x-30)

化简,得y=-8x+2560 (30≤x≤80);

(2)由-8x+2560≤1936得x≥78,因为x为整数,

所以x=78,79,80.所以有3种方案.由函数,

解析式可以看出,当x=80时,y有最小值1920,

所以,运费最低的调运方案是:

从甲仓库调运80台电泵到A厂,调运0台电泵到B厂;

从乙仓库20电泵到A厂,调运50台电泵到B厂.

阅读理解

In so many ways, cyberspace(网络空间) mirrors the real world. People ask for information, play games, and share hobby tips. Others buy and sell products. Still others look for friendship, or even love.

Unlike the real world, however, your knowledge about a person is limited to words on a computer screen. Identity and appearance mean very little in cyberspace. Rather, a person’s thoughts—or at least the thoughts they type—are what really count. So even the shyest person can become a chat-room star.

Usually, this “faceless” communication doesn’t create problems. Identity doesn’t really matter when you’re in a chat room discussing politics or hobbies. In fact, this emphasis on the ideas themselves makes the Internet a great place for exciting conversation. Where else can so many people come together to chat about their interests?

But some Internet users want more than just someone to chat with. They’re looking for serious love relationships. Is cyberspace a good place to find love? That answer depends on whom you ask. Some of these relationships actually succeed. Others fail miserably.

Supporters of online relationships claim that the Internet allows couples to get to know each other intellectually first. Personal appearance doesn’t get in the way.

But critics of online relationships argue that no one can truly know another person in cyberspace. Why? Because the Internet gives users a lot of control over how others view them. Internet users can carefully craft their words to fit whatever image they want to give. And they don’t have to worry about what their “faceless” communication is doing for their image. In a sense, they’re not really themselves.

All of this may be fine if the relationship stays in cyberspace. But not knowing a person is a big problem in a love relationship. With so many unknowns, it’s easy to let one’s imagination “fill in the blanks.” This inevitably leads to disappointment when couples meet in person. How someone imagines an online friend is often quite different than the real person.

So, before looking for love in cyberspace, remember the advice of Internet pioneer Clifford Stoll: “Life in the real world is far richer than anything you’ll find on a computer screen.”

(Note: Answer the questions or complete the statements in NO MORE THAN TEN WORDS.)

小题1:We learn about a person in cyberspace only through  _________________.

小题2:Why is the Internet a great place for exciting conversation?

小题3:What makes online love relationship often fail?

小题4:From the passage we can learn that the writer __________________________ looking for love on the Internet.

单项选择题