某工厂生产D、E两种产品，每种产品均经过3道工序加工而成。假定_爱下问搜题

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问题单项选择题共用题干题

某工厂生产D、E两种产品，每种产品均经过3道工序加工而成。假定每生产1立方米D种产品需用A种机器加工7小时，用B种机器加工3小时，用C种机器加工4小时。而每生产1立方米E种产品需用A种机器加工2.8小时，用B种机器加工9小时，用C种机器加工4小时。又已知每生产1立方米D种产品可赢利500元，每生产1立方米E种产品可赢利800元。现设一个月中A种机器工作时间不得超过560小时，B种机器工作时间不得超过460小时，C种机器工作时间不得超过336小时。为了获取最大赢利每月应该生产D产品约（1）立方米，E产品约（2）立方米。

空白（1）为（）

A.33

B.35

C.49

D.51

答案

参考答案：C

解析：

线性规划题型。设每月应该生产D产品约x立方米，E产品约y立方米。根据题干，可得如下不等式：①7x+2.8y≤560②3x+9y≤460③4x+4y≤336使500x+800y最大首先把①②不等式中的“≤”改为“=”解新的①②，得：X=68.7y=28.2因这对（x=68.7，y=28.2）不满足不等式③，因此为无效解接着对不等式②、③，像上面的方法一样处理，得：X=49.2y=6.7因这对（x=49.2，y=34.7）满足不等式①，因此为有效解最后对不等式①、③，像上面的方法一样处理，得：x=77.3y=6.7因这对（x=77.3，y=6.7）满足不等式②，因此为有效解但显然，（x=49.2，y=34.7）使得500x+800y最大（1）的4个选项中，选项C=49，接近49.2（2）的4个选项中，选项B=35，接近34.7且49、35满足所有的3个不等式。

不定项选择题

某金属元素R的相对原子质量为M，其氧化物的相对分子质量为N，则该金属元素的化合价可能是[ ]

A．(N-2M)/16

B．(N-M)/16

C．(N-M)/8

D．(N-2M)/8

完形填空

I noticed the woman when I entered the newsroom. My secretary told me she wanted to put an ad to   36  a baby. So I suggested several    37 lines for these ads to her:   38 , Baby to love; or Dear Birth Mother, Let Us Help You. The ad would contain   39  about her and her husband: they were   40 , could afford to raise a child. But then something   41  me: the major newspapers carried ads like this and their 42  were larger than ours. “Have you tried the major ones?” I asked. “Yes, but all failed and one more wouldn’t   43 .” She handed me a check and left with a   44  smile.
A week later the woman called in a    45  of delight: “Please don’t run the ad again. We ’ve connected with   46 . The baby is due in a month.” Good news. I asked her if she   47  keep in touch if the adoption   48  to have a happy ending. She agreed but added when the adoption was final she was   49   to give me the story.
One day my phone rang. I   50  her voice immediately. “The adoption is final. Would you like to come and meet him?” Happily, I made a (an ) 51 with her for the next day. “His name is Ben,” she said, as I started to take                  52 . “He slept through the night from the start. Now he’s smiling and starting to turn over. Of course I’m not   53  him. If he is a little slow.” She paused. “ Oh, I should tell you Ben has Down’s Syndrome.(唐氏综合症)” I stopped writing . I wasn’t sure how to   54 . But she smiled “Ben was meant for us, don’t you see? He needs me more than a   55  developing child would.” She sat on the sofa, holding her son. Both of them smiled. “You wanted a story with a happy ending,” said the woman “ You got it.”

D．information

C．considerate

A．occurred to

C．referred to

B．circulations

A．a birth mother

B．a lovely baby

C．an ad company

D．an orphanage

A．turned over

D．turned down

B．comfortable

B．appointment