They sat for hours debating the pros and cons of setting up their own firm.

有计划上大学的中学高年级学生。

(Ⅰ) 假设你有权进行一项控制实验。请说明为了估计hours对sal的引致效应， 你将如何构建实验。

(Ⅱ) 考虑一个更加实际的情形， 即由学生选择在备考课程上花多少时间， 而你只能随机地从总体中抽出sat和hours的样本。将总体模型写作如下形式：

其中，与通常带截距的模型一样， 我们可以假设E(u)=0。列举出至少两个u中包含的因素。这些因素与hours可能呈正相关还是负相关？

(III)在(Ⅱ)的方程中，如果备考课程有效，那么β₁的符号应该是什么？

(Ⅳ)在(Ⅱ)的方程中，β₀该如何解释？

听力原文： American colleges and universities consider a number of things about a student who wants to be admitted. Experts on the subject say the most important thing is the student's high school record. Admissions officers look not only at the grades that the student has earned. They also look at the level of difficulty of the classes.

A student's interests and activities may also play a part in getting accepted. But in most cases another consideration is how well the student did on college entrance exams. This week in our Foreign Student Series Program, we discuss two of these tests: the SAT and the ACT. Most American schools accept either one.

The SAT measures reasoning skills in mathematics and language. Students have almost four hours to complete the SAT. The newest part is an essay. Students have 25 minutes to write an answer to a question.

Students may also need to take SAT subject tests in areas like history, science and foreign language.

The ACT is an achievement test. It is designed to measure what a student has learned in school. Students are tested in mathematics, English, reading and science. A writing test is offered but not required. Without it, the ACT takes about three hours to complete. The essay part adds 30 minutes.

(33)

A．The grade of the ACT or the SAT.

B．The high school the applicant studied.

C．The high school record.

D．The entrance examination.

TV Shows and Long Bus Trips

Long bus rides are like televisions shows. They have a beginning, a middle, and an end — with commercials (商业的) thrown in every three or four minutes. The commercials are unavoidable. They happen whether you want them or not. Every couple of minutes a billboard glides by outside the bus window. "Buy Super Clean Toothpaste." "Drink Good'n Wet Root Beer." "Fill up with Pacific Gas." Only if you sleep, which is equal to turning the television set off, are you spared the unending cry of "You Need It! Buy It Now!"

The beginning of the ride is comfortable and somewhat exciting, even if you've traveled that way before . Usually some things have changed — new houses, new buildings, sometimes even a new road. The bus driver has a style. of driving and it's fun to try to figure it out the first hour or so. If the driver is particularly reckless or daring, the ride can be as thrilling as a suspense (悬念) story. Will the driver pass the truck in time？ Will the driver move into the right or the left—hand lane？ After a while, of course, the excitement dies down. Sleeping for a while helps pass the middle hours of the ride. Food always makes bus rides more interesting. But you've got to be careful of what kind of food you eat. Too much salty food can make you very thirsty between stops.

The end of the ride is somewhat like the beginning. You know it will soon be over and there's a kind of expectation and excitement in that. The seat, of course, has become harder as the hours have passed. By now you've sat with your legs crossed, with your hands in your lap, with your hands on the arm rests —even with your hands crossed Behind your head. The end comes just at no more ways to sit.

According to the passage, what do the passengers usually see when they are on a long bus trip？

A．Buses on the road.

B．Films on television.

C．Advertisements on the board.

D．Gas stations.

Nobody’s Watching Me

I am a foot taller than Napoleon and twice the weight of Twiggy; on my only visit to a beautician, the woman said she found my face a challenge. Yet despite these social disadvantages I feel cheerful, happy, confident and secure.

I work for a daily newspaper and so get to a lot of places I would otherwise never see. This year I went to Ascot to write about the people there. I saw something there that made me realize the stupidity of trying to conform, of trying to be better than anyone else. There was a small, plump woman, all dressed up—huge hat, dress with pink butterflies, long white gloves. She also had a shooting stick. But because she was so plump, when she sat on the stick it went deep into the ground and she couldn't pull it out. She tugged and tugged, tears of rage in her eyes. When the final tug brought it out, she crashed with it to the ground."

I saw her walk away. Her day had been ruined. She had made a fool of herself in public--she had impressed nobody. In her own sad, red eyes she was a failure.

I remember well when I was like that, in the days before I learned that nobody really cared what you do . . .

I remember the pain of my first dance, something that is always meant to be a wonderful occasion for a girl... There was a fashion then for diamante (人造钻石) ear-rings, and I wore them so often practicing for the big night that I got two great sores on my ears and had to put sticking-plaster on them. Perhaps it was this that made nobody want to dance with me. Whatever it was, there I sat for four hours and 43 minutes. When I came home, I told my parents that I had a marvelous time and that my feet were sore from dancing. They were pleased at my success and they went to bed happily, but I went to my room and tore the bits of sticking-plaster off my ears and felt forlorn and disconsolate.

‘The beautician found the writer's face a challenge’, which means _________.

A．she thought it was a challenge to have such a face repaired

B．she thought it was a challenge to deal with such a face

C．the writer's face challenged the beautician's

D．it was a challenge to find the writer's face

阅读材料，回答题。

Long bus rides are like television shows. They have a beginning, a middle, and an end—with commercials thrown in every three or four minutes. The commercials are unavoidable. They happen whether you want them or not. Every couple of minutes a billboard glides by outside the bus win-dow. "Buy Super Clean Toothpaste. "" Drink Root Beer. " "Fill up with Pacific Gas. " Only if you sleep, which is equal to turning the television set off, are you spared the unending cry of "You Need It! Buy It Now !

The beginning of the fide is comfortable and somewhat exciting, even if you&39; ve traveled that way before. Usually some things have changed--new houses, new buildings, sometimes even anew road. The bus driver has a style. of driving and it&39; s fun to try to figure it out the first hour or so. If the driver is particularly reckless or daring, the fide can be as thrilling as a suspense story. Will the driver pass the truck in time？ Will the driver move into the fight or the left-hand lane？ After a while, of course, the excitement dies down. Sleeping for a while helps pass the middle hours of the fide. Food always makes bus rides more interesting. But you&39; ve got to be careful of what kind of food you eat. Too much salty food can make you very thirsty between stops.

The end of the fide is somewhat like the beginning. You know it will soon be over and there&39; sa kind of expectation and excitement in that. The seat, of course, has become harder as the hour shave passed. By now you&39;ve sat with your legs crossed, with your hands in your lap, with your hands on the armrests--even with your hands crossed behind your head, The end comes just at the right time. There are just no more ways to sit.

According to the passage， what do the passengers usually see when they are on a long bus trip？ 查看材料

A.Buses on the road

B.Films on television

C.Advertisements on the board

D.Gas stations

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B.γsat＞γ＞γd＞γ′

C.γsat＞γ＞γ′＞γd

D.γsat＞γ′＞γ＞γd

A.SAT强化班

B.SAT进阶班

C.SAT高分班

D.SAT定制班

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B.γsat ＞ γ ＞ γd ＞ γ′

C.γsat ＞ γ ＞ γ′ ＞ γd

D.γsat ＞ γ′＞ γ ＞ γd

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B.γsat ＞ γ ＞ γ’ ＞ γd

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D.γ ＞ γ’ ＞ γsat ＞ γd

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