25. How did you like the_________ of the interpreter(口译员)at the Chinese FM press conference of 6-party talks on TV?
A. performance B. achievement C. material D. words
24. The man ____ of shooting 16 schoolchildren was returned to Anhui Province police on Friday following his arrest by Beijing police, the Xinhua News Agency reported on Friday.
A. suspected B. suspecting C. being suspected D. to be suspected
23. I wonder what will become of my daughter. _______ endless homework ,she also bears
other leading loads such as revision and recitation.
A. As well as B. With C. Except D. Rather than
22. -I didn’t know you were good friends .
-You___________. I have known her since she moved here. You were studying abroad then.
A. may have B. needn’t have C. couldn’t have D. must have
22.(本小题满分15分)
(Ⅰ)设M,N为短轴的两个三等分点,因为△MNF为正三角形,
所以, 即1= 因此,椭圆方程为 (5分)
(Ⅱ)由题意可得抛物线方程为: (7分)
设,直线不可能为轴,故可设直线为
,
由韦达定理可得:, (9分)
的面积,
又, (13分)
,取到最小值16,即的最小值为4
最小值为4
,即直线垂直轴时,面积最小,最小值为4 (15分)
21.(本小题满分15分)
解:(1)f(x)=ax34ax2+4ax
f/(x)=3ax28ax+4a=a(3x2)(x2)=0x=或2
∵f(x)有极大值32,而f(2)=0 ∴f()=,a =1 (7分)
(2)f/(x)=a(3x2)(x2)
当a>0时,f(x)在[ 2,]上递增,在[]上递减,,
∴0<a<27 (10分)
当a<0时,f(x)在[2,]上递减,在[]上递增,f(2)= 32a>f (1)=a
,即 ∴ (13分)
综上 (15分)
20.(本小题满分14分)
解:(1) (2分)
当时, (4分)
∴,即
∴是公比为3的等比数列 (6分)
(2)由(1)得: (8分)
设的公差为(), ∵,∴ (10分)
依题意有,,
∴
,得,或(舍去) (12分)
故 (14分)
19. (本小题满分14分)
解:(1)由已知 (7分)
(2)由 (10分)
由余弦定理得 (14分)
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