如图所示,直线OAC为某一直流电源的总功率P总随电流I变化的图线,抛物线OBC为

题型:不定项选择

问题:

如图所示,直线OAC为某一直流电源的总功率P随电流I变化的图线,抛物线OBC为该电源内部热功率Pr随电流I变化的图线,则根据图线可知

[ ]

A.电源电动势为6V

B.电源内阻为1.5Ω

C.当电路中电流为1A时,外电路的电阻为1.5Ω

D.在O→C过程中,电源输出功率的变化是先变大再变小

考点:闭合电路的功率
题型:不定项选择

When I was growing up, I was embarrassed to be seen with my father. He (1) severely crippled and very short, and when we would walk together, his hand on my arm (2) balance, people would stare. I would inwardly be afraid (3) squirm at the unwanted attention. If he ever noticed or was bothered, he never let (4) .
It was difficult to coordinate (5) steps - his halting, mine impatient - and because of that, we didn’t say much as we went along. But as we started out, he always said, "You (6) the pace. I will try to adjust to you. "
Our usual walk was to or (7) the subway, which was how he got to (8) . He went to work sick, and (9) nasty weather. He almost never missed a day, and would (10) it to the office even if (11) could not: a matter of pride!
He never talked about himself as an object of pity, (12) did he show any envy of the more fortunate or able. What he looked for in others was a "good heart", and if he found one, the owner was good enough for him.
Now that I am older, I believe that is a proper standard (13) which to judge people, even though I still don’t know precisely (14) a "good heart" is. But I know the times I don’t have one myself.
He has (15) gone many years now, but I think (16) him often. I wonder if he sensed my reluctance to be seen with him during our (17) . If he did, I am (18) I never told him how sorry I was, how unworthy I was, how I regretted it. I think of him when I complain about trifles, when I am (19) of another’s good fortune, when I don’t have a "good heart".
At such times I put my hand on his arm to regain my (20) , and say, "You set the pace, I will try to adjust to you.\

题型:不定项选择

乳前牙反,仅覆深者应采用那种矫治方法()

A.调磨法

B.上颌垫式活动矫治器附双曲舌簧

C.下颌联冠式斜面导板

D.头帽颏兜牵引矫治器

E.单侧垫式活动矫治器

题型:不定项选择

The questions in this group are based on the content of a passage. After reading the passage, choose the best answer to each question. Answer all questions following the passage on the basis of what is stated or implied in the passage.

The collapse of the stock "bubble" of Internet-related companies in 2000-2001 has resulted in more than its fair share of analysis, hand-wringing, and finger-pointing. A panel discussion at a recent Technology Today conference in Santa Monica produced a heated debate between two former luminaries of the dot.corn world: investment banker Pat Verhofen and Sue Mickelson, founder and CEO of Internet retailer Frizbeez.com.

Verhofen fired the opening shot by placing blame for the collapse of Internet stocks on the shoulders of Internet entrepreneurs who aggressively promoted ideas without viable business models. These entrepreneurs were both irresponsible and deceptive, Verhofen argued, to take investors’ money to fund operations that could not reasonably turn a profit, such as giving computers away for free or selling bulky objects, such as dog food or furniture, over the Internet. Many of these companies, he suggested, were little more than arrangements of smoke and mirrors designed to separate investors from their money.

Mickelson responded that Verhofen was like a fox in a henhouse blaming the rooster for all the dead chickens. Entrepreneurs cannot be blamed, she argued, for trying to make money for themselves and other people, because that is what entrepreneurs do. She also stated that you cannot know what ideas will or will not work until you try them; contemporaries of the Wright brothers said that a heavier-than-air aircraft could never work, and look at the skies today.

Mickelson instead placed the blame on the unscrupulous bankers and fund managers who hyped Internet stocks in order to cash in on fees from IPOs and trades. In contrast to entrepreneurs, these financial types actually do have a responsibility to offer only sound financial advice to their clients. If anyone should bear the blame, she argued, it should be people like Pat Verhofen.

Indigo Smith, the moderator of the panel, responded that perhaps the true fault lay with the common investors, who should not have invested in technology stocks in the first place if they lacked the knowledge to do so properly. While she expressed sympathy for those elderly investors who lost substantial portions of their retirement savings on flimsy Internet stocks, she observed that no one forced them to invest in those stocks.

Which of the following statements presents the pest conclusion one could draw based on the information given in the passage ?()

A. The collapse of the Internet stock "bubble" drove thousands of investors into bankruptcy.

B. People involved with the Internet do not all agree on which party bears the most responsibility for the collapse of the Internet stock "bubble."

C. Of all parties involved with the Internet, financial professionals such as investment bankers and fund managers derived the most profits from the stock "bubble."

D. The Internet stock "bubble" could not have occurred if entrepreneurs had been honest about the true financial prospects of their companies.

E. The average investor has no one to blame but himself or herself if he or she invested in an Internet stock without adequately understanding the true financial prospects of the companies in question.

题型:不定项选择

半数以上孕妇大约多少周后产生血型抗体()

A.26周

B.24周

C.28周

D.30周

E.32周

题型:不定项选择

工业项目的试生产分为两个阶段()

A.试运行(试车)

B.试生产考核

C.试车

D.试预算

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