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【简答题】
某公司为研究职工上班从家里到单位的时间,抽取了由 16 个人组成的一个随机样本,他们自驾车上班到单位的时间(单位:分钟)如下: 15 22 12 19 33 52 27 40 48 35 75 28 47 61 33 13 假定该公司职工自驾车上班的时间服从正态分布,在 99 %的置信水平下,估计: ( 1 )该公司职工自驾车上班平均时间的置信区间。 ( 2 )如果已知总体标准差为 20 分钟,估计该公司职工自驾车上班平均时间的置信区间。 ( 3 )如果已知总体标准差为 20 分钟,若要求估计误差不超过 10 分钟,应抽取多少职工进行调查?(注 , )
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【单选题】In the next century we'll be able to alter our DNA radically, encoding our visions and vanities while concocting new life-forms. When Dr. Frankenstein made his monster, he wrestled with the moral issu...
A.
to give an episode of the DNA technological breakthroughs.
B.
to highlight the inevitability of a means to some evil ends.
C.
to show how he created a new form. of life a thousand years ago.
D.
to introduce the topic of moral philosophies concerning biotechnology.
【单选题】Would you mind joining for the picnic tomorrow? ().
A.
So sorry. Next time we'll go. Thanks anyway.
B.
OK, thank you.
C.
No, thanks.
【单选题】听力原文： The next house we'll be looking at is in a quiet area of town. It's only 5 years old. It has 2 stories, 3 bedrooms, and an enormous backyard. The previous owner was a landscaper, so the house an...
A.
An actor
B.
A landscaper
C.
An architect
D.
A photographer
【简答题】工厂所需电力容量不大于160KVA.时，通常采用（）进线，直接由当地的公用电网供电，＞160KVA.且＜1000KVA.采用（）进线，＞1000KVA.时采用（）进线。
【单选题】－ Next week we'll have the final English exam. － Yes? Then, every minute must be made full use ________ English. [ ]
A.
of studying
B.
to study
C.
of being studying
D.
of to study
【单选题】In the next century we'll be able to alter our DNA radically, encoding our visions and vanities while concocting new life-forms. When Dr. Frankenstein made his monster, he wrestled with the moral issu...
A.
to give an episode of the DNA technological breakthroughs.
B.
to highlight the importance of a means to some everlasting ends.
C.
to show how he created a new form. of life a thousand years ago.
D.
to introduce the topic of moral philosophies incurred in biotechnology.
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