单项选择题
1、 A，B是抛物线Y 2—8x上两点，且此抛物线的焦点在线段AB上，已知A，B两点的横坐标之和为l0，则 （    ）
A．18    
B．14
C．12    
D．10


2、 If I find someone who looks like the suspect, my__________ reaction will be to tell the police．
A．physi．cal
B．immediate
C．sensitive
D．sudden


3、 My birthday is on__________Friday this year．
A．不填
B．a
C．an
D．the

4、阅读下列短文，回答题。
     Most musicians agree that the best violins(小提琴) were made in Cremona, Italy, about 200years ago． They even sound better than violins made today． Violin makers and scientists try to makeinstruments(乐器)like the Italian violins,however,they are not the same． Why are these old Italianviolins so special? No one really knows． But many people think they have an answer．
     Some people think it is the age of the violins． But there is a problem here． Not all old violins
     sound wonderful． Only the old violins from Cremona are special． So age cannot be the answer．
     Other people think the secret to those violins is the wood． It must be from certain kinds of trees．It must not be too young or too old． Perhaps the violin makers of Cremona knew something specialabout wood for violins．
     But the kind of wood may not be so important． It may be more important to cut the wood in aspecial way． Wood for a violin must be cut into the right size and shape． The smallest difference willchange the sund of the violin． Musicians sometimes think that this is the secret of the Italians．
     Size and shape may not be the answer either． Scientists make new violins that are exactly the  same size and shape． But the new ones still do not sound as good as the old ones． Some scientiststhink the secret may be the varnish (清漆)．It makes the wood look shiny, but it also helps the soundof the instrument． Since no one knows what the Italian violin makers used in their varnish, no one canmake the same varnish today．
There may never be other violins like the violins of Cremona． And there are not many of the old
     violins left． So these old violins from Cremona become more and more precious．
What would be the best title for the text?
A．The Secrets of Cremona Violins．
B．The History of Cremona Violins．
C．The Making of Italian Violins．
D．The Studies of Italian Violins．


5、 函数y=cos⁴x-sin⁴x的小正周期是
A．4π
B．2π
C．π
D．π/2


6、
若向量a=(1，2)，b=(－3，4)，则(a·b)(a+b)等于
A．20
B．(－10，30)
C．54
D．(－8，24)


7、 已知函数f(x)=-x²+6x，则f(x)的
A．小值为-9
B．值为9
C．值为-9
D．小值为0


8、 直线Y=ax+2与直线Y=3x-b关于直线y=x对称，则(  )
 


填空题
9、


简答题
10、圆柱金属饮料罐的容积V一定时，它的高与底半径R怎样选取，才能使所用材料省?

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