单项选择题
1、
函数f(x)的解析式是    (     )
 


2、 以下有关郑和下西洋的表达，错误的一项是（　　）
A．发生在明成祖时期
B．当时的西洋是指今天的大西洋
C．先后7次航海，到达了30多个国家
D．创造了世界航海史上的纪录


3、 标志美国独立战争开始的事件是（　　）
A．波士顿倾茶事件
B．来克星顿枪声
C．第二届大陆会议召开
D．萨拉托加大捷


4、 There' s no light on--they__________ be at home．
A．can't
B．mustn't
C．needn't
D．shouldn't


5、



6、 等差数列{a_n}的前三项分别为a-1，a+1，2a-3，则该数列的通项是
A．2n-5
B．2n-3
C．2n+5
D．2n+3


7、 阅读下列短文，回答题。
Mr. White worked in an office. He had neither a wife nor children. And he lived in an old house alone. He liked nothing but drinking. He almost spent all his money on it. Sometimes he was hungry,because he even had no money to buy food. So he had to borrow some money from his workmates.
One evening he met a friend of his in the street. The man asked him to have dinner in a restaurant. He was very happy and drank a lot. When they left there at midnight, he could hardly stand. The friend had to stop a taxi and asked the diver to take him home. Soon they arrived at the door of his house. With the help of the driver he got out of the taxi.
"Thank you,sir," said Mr. White. "Now I can open the door myself. "
The taxi went away, but Mr. White couldn't put his key into the keyhole. He was trying to do it when a policeman came.
"Can I help you?" asked the policeman.
"Thank you , sir, " said Mr. White. "The house is circling now. If you can stop it moving, I can open the door myself. "
Sometimes he was hungry because__________.
A．he spent all his money on drinks and had no money to buy food
B．he had no work
C．his boss didn't pay him any money
D．he was very poor


8、
A．A
B．B
C．C
D．D


简答题
9、如图5-9所示，在高h=10 m的平台上，放一个质量m₁=9．9 kg的木块，它与平台边缘的距离为l=1．0m．今有一颗质量m₂=0．1 kg的子弹以水平向右的速度v₀=500 m／s射入木块，并留在木块中．木块与平台间的摩擦因数μ=0．45，求：(取g=10 m／s²．)
(1)子弹射入木块过程中，木块所受冲量的大小；
(2)木块离开平台边缘时的速度；
(3)木块落地时与平台边缘的距离．



10、 证明a，b，c成等差数列．

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