二、填空题（每小题3分，共24分）
71a） 11． 12．60° 13．3
21014．12000 15．△ABD≌△CDB（或△ADE≌△CDE或△ABE≌△CBE） 16．2π
9．2 10．0.7a（或70%a或
三、解答题（每小题6分，共18分） 17．有两种情形： ·················································································································· 2分
注：每图2分．
2xyx2?y2(x?y)2x?y18．选择一：M?N?2， ····························· 4分 ???x?y2x2?y2(x?y)(x?y)x?y5y?y572当x∶y=5∶2时，x?y，原式=·························································· 6分 ?． ·523y?y22xyx2?y2?(x?y)2y?x选择二：M?N?2， ····································· 4分 ???x?y2x2?y2(x?y)(x?y)x?y5y532当x∶y=5∶2时，x?y，原式=······················································· 6分 ??． ·527y?y2y?x2?y22xy(x?y)2x?y选择三：N?M?2， ····································· 4分 ???x?y2x2?y2(x?y)(x?y)x?y5y?y532当x∶y=5∶2时，x?y，原式=·························································· 6分 ?． ·527y?y2注：只写一种即可．
??DAC??ACB，?AD?DC，??DCA??DAC，19．（1）?AD∥BC，
11?DCB，?DC?AB，??DCB??ABC，??ACB??ABC． 22??CAB?90°，在△ACB中，?AC?AB， 1??ACB??ABC?90°，??ABC??ABC?90°，?ABC?60°； ···························· 3分
2（2）连接DB．?在梯形ABCD中，AB?DC，?AC?DB， 在四边形DBFA中，DA∥BF，DA?DC?BF， ?四边形DBFA是平行四边形，?DB?AF， ??DCA??ACB?
?AC?AF，即△ACF为等腰三角形． ··········································································· 6分
四、应用题（每小题8分，共32分） 20．（1）设y?kk10，在图象上，?10?，即k?1?10?10，?y?，其中，?A(110)x1x1≤x≤10； ························································································································· 4分
（2）答案不唯一．例如：小明家离学校10km，每天以vkm/h的速度去上学，那么小明从
10家去学校所需的时间t?． ······························································································· 8分
v5553≈9103（亿元）=9.103?1011（元）21．（1）； ······················································ 2分 61%（2）360°?15%?54°； ····································································································· 4分 （3）B、D； ························································································································ 6分
（4）答案不唯一．例如：中央政府非常重视农田水利等农村民生工程问题． ················· 8分
，AB?200，AF?22．在Rt△ABF中，?AFB?37°BF?AB≈333，
sin37°AB≈267， ········································································································ 4分
tan37°?BC∥EF，BF∥CE，?四边形BCEF为平行四边形．?CE?BF?267， BC?EF?100．
在Rt△CDE中，?DCE?53°，CD?DE，??CED?37°， DE?CE·cos37°?214，CD?CE·sin37??160， ······················································ 7分
?增加的路程=(AF?EF?DE)?(AB?BC?DC)≈(333?100?214)?
(200?100?160)?187（米）． ·························································································· 8分
23．（1）设需A种灯笼x个，B种灯笼y个，根据题意得：
?x?y?200，? ························································································································· 4分 2?y?x，?3?解得??x?120， ························································································································ 6分
y?80；?（2）120×40+80×60=9600（元）． ····················································································· 8分 五、阅读理解题（10分） 24．（1）22(5?3)2(5?3)······················ 2分 ???5?3， ·225?3(5?3)(5?3)(5)?(3)2(5)2?(3)2(5?3)(5?3)····································· 2分 ???5?3； ·
5?35?35?3（2）原式=3?15?37?5 ??(3?1)(3?1)(5?3)(5?3)(7?5)(7?5)
?…?2n?1?2n?1 ··································································· 7分
(2n?1?2n?1)(2n?1?2n?1)=
3?15?37?52n?1?2n?1 ··················································· 9分 ???…?22222n?1?1． ····················································································································· 10分 2=六、综合题（12分）
0)B0，4）25．（1）当x?0时，y?4；当y?0时，x?4．?A(4，，（； ······················· 2分 ?（2）?MN∥AB，OMOA11??1，?OM?ON?t，?S1?OM·ON?t2； ···· 4分 ONOB22（3）①当2?t≤4时，易知点P在△OAB的外面，则点P的坐标为(t，t),
F点的坐标满足??x?t，4?t)， 即F(t，?y??t?4，同理E(4?t，t)，则PF?PE?t?(4-t)?2t?4， ······················································· 6分 所以S2?S△MPN?S△PEF?S△OMN?S△PEF
11113?t2?PE·PF?t2?(2t?4)(2t?4)??t2?8t?8； ······································ 8分 222221212515??4?4?， ②当0?t≤2时，S2?t，t?221622解得t1??5?0，t2?5?2，两个都不合题意，舍去； ··············································· 10分
3257t?8t?8?，解得t3?3，t4?， 22375综上得，当t?或t?3时，S2为△OAB的面积的． ·············································· 12分
316当2?t≤4时，S2??注：解答题用其它方法解答，请参照评分．