阅读理解
George Stephenson was born in 1781 in a poor family. He had to start work when he was only eight. When George was fourteen, he became his father’s helper. He spent a lot of time learning about engines. And on holidays he often took one to pieces and studied each piece carefully. Soon he became a very good worker though he could not read or write. He began to learn the English letters when he was seventeen years old. Every day after he did twelve hours of hard work, he walked a long way to have lessons from a young school teacher. On his eighteenth birthday, he wrote his own name for the first time in his life. George invented many things in his life. The train was the greatest one among them. Today when we watch or take trains from one place to another, we will think of this great man -- George Stephenson.
小题1: In which year did George Stephenson start to help his father?
A．In 1781.
B．In 1789.
C．In 1795.
D．In 1798.小题2: He learned about the engine ______.
A．through reading and writing
B．by taking it to pieces and studying each piece carefully
C．at lessons from a young teacher
D．by asking a lot of questions小题3: He spent a lot of time learning about engines and soon became ______.
A．a great man
B．a good maker
C．a good worker
D．a good student小题4: George Stephenson ______ in his childhood.
A．didn’t go to school
B．had lessons from a very good teacher
C．lived an easy life
D．invented the train小题5: The passage tells us ______.
A．everybody should work hard for a living
B．one can start studying at school at the age of 18
C．George Stephenson liked working very much
D．hard work leads to success
56×5角钢(A=2×541.5=1083mm2，imin=21.7mm)；下柱支撑设置一道，其斜杆的长度l1=9.12m，采用2[8槽钢(A=2×1024=2048mm4，imin=31.5mm)。柱的截面宽度b=400mm。钢材用Q235钢。水平地震作用标准值如图(b)所示。取γRE=0.8。