Youpay – it's free（）

A nylon bar (E = 2.1 GPa) with diameter 12 mm, length 4.5 m, and weight 5.6 N hangs vertically under its own weight. The elongation of the bar at its free end is approximately:

A、0.05 mm

B、0.07 mm

C、0.11 mm

D、0.17 mm

A cantilever wood pole carries force P =300 N applied at its free end, as well as its own weight (weight density = 6. The length of the pole is L = 0.75 m and the allowable bending stress is 14 MPa. The required diameter of the pole is approximately:

A、4.2 cm

B、5.5 cm

C、6.1 cm

D、8.5 cm

A.9 m/s

B.18 m/s

C.90 m/s

D.900 m/s

E.60 m/s

F.600 m/s

A cantilever beam AB is loaded by a coupleat its free end (see fgure). The length of the beamis L=2.0 m , and the longitudinal normal strain at the top surface is=0.0010 . The distance from the top surface of the beam to the neutral surface is c =85 mm . (a) Calculate the radius of curvature, the curvature, and the vertical deflectionat the end of the beam. (b) If allowable strain=0.0008 , what is the maximum acceptable depth of the beam？ [Assume that the curvature is unchanged from part(a)]. (c) If allowable strain= 0.0008 , c = 85 mm , and L= 4 m , what is deflection？

听力原文：W: Excuse me, is that seat taken？

M: No, it's free, I think.

W: Right, I'll take it. Here I am. I thought I'd never make it.

M: What, catching the plane？

W: Yes, my brother insisted on driving out to the airport. The traffic was terrible, there being an accident or something.

M: I always travel on the airport bus. I know you waste a certain amount of time waiting around doing nothing. But at least you're certain that you'll be on time for the plane.

W: You're right. Better late than never. But of course, better never late. I try to make it at exactly 11 o'clock. That's when our flight is supposed to take off.

M: See they are starting to check on the seat belts. I suppose it won't be long now.

W: The take-off is the only interesting thing about flight, in my opinion.

M: Well, I don't know. Landing can have its moment especially when the weather is bad.

W: Oh, that reminds me. The weather report this morning said sunny and warm. I don't see any clouds. So we'11 be fine.

Where are the speakers？

A．On a plane.

B．On an airport bus.

C．In the waiting room.

public throughout the year. These involve not only amateur performers, but professional artists as well. The public parks of many cities across the country usually have bandstands and large lawns. As a service to citizens, they rent out space to performers free of charge. Amateur groups, with nothing more than a desire to perform. offer their talents freely to public. Semi-professional artists are pleased to get the chance to perform. before the public to perfect their craft and nurture the hope of being discovered before beginning a professional career. Famous professionals also give free concerts to make contact with their admiring fans. Often such concerts are sponsored by a large corporate organization and offered to the public free of charge as a cultural service and support for the arts.

The free concerts feature all kinds of music from rock and roll, jazz, country, western to the classics. In addition, free performances may include the plays of Shakespeare or experimental theatre of modern dramatists. In New York's Central Park there has long been a summer Shakespeare festival which draws huge crowds to the free performances.

Of these concerts the ones held on a summer evening in the park are the most popular. They take on a festive air. Friends and groups gather together after work and spread out a blanket on the lawn facing the performers' stage. The early comers get the best locations and enjoy a picnic supper while it is still daylight. The free seating is on a first come basis. Therefore, by the time the concert begins, as many as five thousand or more people may be in attendance. The concerts usually begin at 8 p. m and are performed under the stars. The sound is made sufficiently loud so that no matter where one chooses to sit, he can hear very well. The only disturbance may be the sound of an overhead airplane on its final approach to an airport or the far-off siren(警笛声) of an ambulance on its way to the hospital. This matters little! What counts is to soak up the atmosphere created by the music and to be with friends in the fresh open air. The best part of it all is that it's free!

Many American parks give free concerts on their lawns because they______.

A．have the necessary facilities

B．call attract more visitors

C．want to serve the public

D．are in a position to invite musicians

public throughout the year. These involve not only amateur performers, but professional artists as well. The public parks of many cities across the country usually have bandstands and large lawns. As a service to citizens, they rent out space to performers free of charge. Amateur groups, with nothing more than a desire to perform. offer their talents freely to public. Semi-professional artists are pleased to get the chance to perform. before the public to perfect their craft and nurture the hope of being discovered before beginning a professional career. Famous professionals also give free concerts to make contact with their admiring fans. Often such concerts are sponsored by a large corporate organization and offered to the public free of charge as a cultural service and support for the arts.

The free concerts feature all kinds of music from rock and roll, jazz, country, western to the classics. In addition, free performances may include the plays of Shakespeare or experimental theatre of modern dramatists. In New York's Central Park there has long been a summer Shakespeare festival which draws huge crowds to the free performances.

Of these concerts the ones held on a summer evening in the park are the most popular. They take on a festive air. Friends and groups gather together after work and spread out a blanket on the lawn facing the performers' stage. The early comers get the best locations and enjoy a picnic supper while it is still daylight. The free seating is on a first come basis. Therefore, by the time the concert begins, as many as five thousand or more people may be in attendance. The concerts usually begin at 8 p. m and are performed under the stars. The sound is made sufficiently loud so that no matter where one chooses to sit, he can hear very well. The only disturbance may be the sound of an overhead airplane on its final approach to an airport or the far-off siren(警笛声) of an ambulance on its way to the hospital. This matters little! What counts is to soak up the atmosphere created by the music and to be with friends in the fresh open air. The best part of it all is that it's free!

Many American parks give free concerts on their lawns because they______.

A．have the necessary facilities

B．call attract more visitors

C．want to serve the public

D．are in a position to invite musicians

Passage 4

America’s most popular newspaper website today announced that the era of free online journalism is drawing to a close. The New York Times has become the biggest publisher yet to set out plans for a paywall around its digital offering, _1_ the accepted practice that internet users will not pay for news. Struggling with an evaporation of advertising and a downward drift in street corner sales, The New York Times intends to introduce a “metered” model at the beginning of 2011. Readers will be required to pay when they have _2_ a set number of its online articles per month. The decision puts the 159-year-old newspaper on the charging side of an _3_ wide chasm (鸿沟）in the media industry. But others, including the Guardian, have said they will not _4_ internet readers. The New York Times&39;s publisher, Arthur Sulzberger, _5_ that the move is a gamble. Boasting a print _6_ of 995,000 on weekdays and 1.4 million on Sundays, The New York Times is the third bestselling American newspaper, behind the Wall Street Journal and USA Today. While most US papers focus on a single city, The New York Times is among the few that can claim _7_ scope—as well as 16 bureaus in the New York area, it has 11 offices around the US and maintains 26 bureaus elsewhere in the world. But like many in the publishing industry, the paper is in the grip of a _8_ financial crisis. Its parent company, the New York Times Company, has 15 papers, but _9_ a loss of $70 million in the nine months to September and recently accepted a $250 million _10_ from a Mexican billionaire， Carlos Slim, to strengthen its balance sheet.

A) national

B) interactively

C) circulation

D) loan

E) crude

F) exceeded

G) charge

H) ascend

I) abandoning

J) suffered

K) serious

L) deducting

M) increasingly

N) evaluation

O) acknowledged

第1空答案是：

听力原文：W: Excuse me, is that seat taken？

M: No, it's free, I think.

W: Right, I'll take it. Here I am. I thought I'd never make it.

M: What, catching the plane？

W: Yes, my brother insisted on driving out to the airport. The traffic was terrible, there being an accident or something.

M: I always travel on the airport bus. I know you waste a certain amount of time waiting around doing nothing. But at least you're certain that you'll be on time for the plane.

W: You're right. Better late than never. But of course, better never late. I try to make it at exactly 11 o'clock. That's when our flight is supposed to take off.

M: See they are starting to check on the seat belts. I suppose it won't be long now.

W: The take-off is the only interesting thing about flight, in my opinion.

M: Well, I don't know. Landing can have its moment especially when the weather is bad.

W: Oh, that reminds me. The weather report this morning said sunny and warm. I don't see any clouds. So we'11 be fine.

Where are the speakers？

A．On a plane.

B．On an airport bus.

C．In the waiting room.

oday about the political management of the war on both sides: the north under Abraham Lincoln and the south under Jefferson Davis. An important task for both of these presidents was to justify for their citizens just why the war was necessary.

W: It started in 1861, on July 4th when Lincoln gave his first major speech, right？

M: Yes, in the speech he presented the northern reasons for the war. It was, he said, to preserve democracy, Lincoln suggested that this war was a noble campaign that would determine the future of democracy throughout the world. For him the issue was whether or not this government of the people, by the people could maintain its integrity, could it remain complete and survive its domestic foes. In other words, could a few discontented individuals and by that he meant those who led the southern rebellion, could they break up the government and put an end to free government on earth？

W: The best way for the nation to survive was to crush the rebellion, right？

M: At the time, he was hopeful that the war wouldn't last long and the slave owners would be put down forever, but he underestimated how difficult the war would be. It would be harder than any the Americans had thought before or since, largely because the north had to break the will of the southern people, not just by its army. But Lincoln rallied northerners to a deep commitment to the cause and achieved the success.

(23)

A．Advantages of the north in the Civil War.

B．Civilian opposition to the Civil War.

C．Reasons to justify fighting the Civil War.

D．Military strategy used in the Civil War.