We were both searching for our separate identities.

Twin Towers did a good job in designing the buildings. The buildings were safe from the hazards

envisioned (预想到的) at the time. Indeed, they were designed to withstand the force of aircraft that might crash into them. They were not however, designed to withstand the effects of the very high temperatures

produced by the ignition (点燃) of aviation fuel carried by the aircraft.

Steel lightly covered with concrete is the main structural part of the towers and steel loses a lot of

structural strength when heated to 1100 degrees Centigrade and beyond, as it was. To protect the steel the towers beams were coated with a few centimeters of concrete. That insulation (隔离) was to provide

structural state of being complete for at least 1 hour of fire. The towers met that test. The south tower

lasted 62minutes. The north, 103 minutes. Tragedy followed when not all could escape before the

collapse.

Most experts agree that the Twin Towers were very well designed. Many also agree that the people

planning the attacks were very knowledgeable and aimed the aircraft at a height that would produce the

most damage. The aircraft crash and the resulting fuel fed fires were aimed at about the 90th floor. That

was just high enough to insure that the upper floors would weaken with the heat and crack down, dropping into the remaining part of the building.

The mass of the falling top floors created such a falling load that some experts estimate it exceeded by 5 to 10 times normal bearing loads. The effect was like a giant hammer, each floor contributing more weight

to be born by the next floor down.

Were the Trade Towers well designed？ Engineers say yes. But, the public holds to the belief that

architects will never again design a tall building without considering the effects of terrorist attacks of all

potential kinds. That not only includes the ability of the structure to withstand attack but the means to allow the buildings occupants to escape in time to survive.

B. it could withstand any natural hazards such as earthquake or fire

C. it had an attracting and beautiful appearance until they were destroyed

D. they had the miserable honor of being selected as the target of terrorist attack

B. the tower held stable until all of the people in there managed to escape

C. the tower can be immune to such attacks

D. they considered more about the effects of the very high temperatures and made duel(决定性的)

changes in the structure

B. cracked down because of the burning

C. was hammered down by the falling upper part

D. was safe after the attack

B. were well-designed

C. were good examples for engineers of our time

D. were out of consideration when we talk about engineering later

his family in a house in Austin, Texas, which is now a museum. Visitors to Austin can see the house. It was

saved from destruction (破坏) and turned into a museum in1934. The museum is a good way to learn about

the interesting life of the American writer.

William Porter rented this house in Austin and lived there with his wife Athol and daughter Margaret for

about two years. Many objects in the museum belonged to the Porters. Others did not. An important piece in

the room is the original photograph over here. It was taken there in the house about 1895. The piano there goes

back to the 1860s. His wife took lessons on it when she first moved to Austin.

Porter did not start his career as a successful writer. He worked at a farm, land office and bank. He also

loved words and writing. The museum has a special proof (证明) of Porter's love of language- his dictionary.

It is said that he had read every word in that dictionary.

Later William Porter was forced to leave Austin because he was charged (指控) with financial wrongdoing

at the bank and lost his job. Because he was afraid of a trail (审判), he left the country secretly. But he

returned because his wife was dying. After her death, he faced the trial and became a criminal. He served three

and a half years in a prison in Ohio.

William Porter would keep his time in prison a secret. But there was one good thing about it. It provided

him with time to write. By the time he was freed, he had published 14 stories and became well known as

O.Henry.

Porter later moved to New York City and found great success there. He published over 180 stories in the

last eight years of his life.

B more visitors will be attracted to Austin

C. visitors can learn about O.Henry's life

D. it can show the way of life in the 1860s

B. It has a long history of about 150 years.

C. Porter's wife gave music lessons on it.

D. Porter usually created music on it.

B. With the records they keep.

C. Using the books they wrote.

D. Using the photograph they keep.

B. He didn't want to make trouble.

C. He meant to save his wife's life.

D. He was charged with a crime.

B. Porter spent his time in prison writing

C. Porter suffered (遭罪) a lot from his time in prison

D. life in prison provided what he could write for Porter