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更多“—__theweather（）”相关的问题
Could youreproduce Silicon Valley elsewhere, or is there something unique about it？
It wouldn’t besurprising if it were hard to reproduce in other countries, because youcouldn’t reproduce it in most of the US either. What does it take to make aSilicon Valley？
It’s the rightpeople. If you could get the right ten thousand people to move from SiliconValley to Buffalo, Buffalo would become Silicon Valley.
You only needtwo kinds of people to create a technology hub （中心）:rich people and nerds （痴迷科研的人）.
Observationbears this out. Within the US, towns have become startup hubs if and only ifthey have both rich people and nerds. Few startups happen in Miami, forexample, because although it’s full of rich people, it has few nerds. It’s notthe kind of place nerds like.
WhereasPittsburg has the opposite problem: plenty of nerds, but no rich people. Thetop US Computer Science departments are said to be MIT, Stanford, Berkeley, andCarnegie-Mellon. MIT yielded Route 128. Stanford and Berkeley yielded SiliconValley. But what did Carnegie-Mellon yield in Pittsburgh？ And whathappened in Ithaca, home of Cornell University, which is also high on the list.
I grew up inPittsburgh and went to college at Cornell, so I can answer for both. Theweather is terrible, particularly in winter, and there’s no interesting oldcity to make up for it, as there is in Boston. Rich people don’t want to livein Pittsburgh or Ithaca. So while there are plenty of hackers （电脑迷）who could start startups, there’s no one to invest in them.
Do you reallyneed the rich people？ Wouldn’t it work to have the government invest the nerds？No, it would not. Startup investors are a distinct type of rich people. Theytend to have a lot of experience themselves in the technology business. Thishelps them pick the right startups, and means they can supply advice andconnections as well as money. And the fact that they have a personal stake inthe outcome makes them really pay attention.
56. What do welearn about Silicon Valley from the passage？
A) Its success is hard to copy any where else.
B) It is the biggest technology hub in the US.
C) Its fame in high technology is incomparable.
D) It leads the world in information technology.
57. What makesMiami unfit to produce a Silicon Valley？
A) Lack of incentive for investments.
B) Lack of the right kind of talents.
C) Lack of government support.
D) Lack of famous universities.
58. In that wayis Carnegie-Mellon different from Stanford, Berkeley and MIT？
A) Its location is not as attractive to rich people
B) Its science department are not nearly as good
C) It does not produce computer hackers and nerds
D) It does not pay much attention to business startups
59. What doesthe author imply about Boston？
A) It has pleasant weather all year round.
B) It produces wealth as well as high-tech
C) It is not likely to attract lots of investor and nerds.
D) It is an old city with many sites of historical interest.
60. What doesthe author say about startup investors？
A) They are especially wise in making investments.
B) They have good connections in the government.
C) They can do more than providing money.
D) They are enough to invest in nerds.
已知某系统由以下方程式组成，试绘制出系统的结构图并求传递函数
。
X1(s)=G1(s)R(s)-G1(s)[G7(s)-G8(s)]C(s)
X2(s)=G2(s)[X1(s)-G6(s)X3(s)]
X3(s)=[X2(s)-G5(s)C(s)]G3(s)
C(s)=G4(s)X3(s)
A.'a'＜=s＜='z'
B.（s>='a'） && （s＜='z'）
C.（s>='a'） & （s＜='z'）
D.（'a'＜=s） and （'z'>=s）
A.13Kbit/s；16Kbit/s；22.8kbit/s
B.16kbit/s；22.8kbit/s；30kbit/s
C.13kbit/s；22.8kbit/s；270kbit/s
D.13kbit/s；16kbit/s；270kbit/s
