脑出血最好发的部位在（） A.脑桥 B.内囊 C.小脑 D.大脑皮质 E.中脑

已知:a、b、c为△ABC的三边,且满足a²c²-b²c²=a⁴-b⁴,试判断△ABC的形状.

解:∵a²c²-b²c²=a⁴-b⁴,①

∴c²(a²-b²)=(a²+b²)(a²-b²).②

∴c²=a²+b².③

∴△ABC是直角三角形.

问:

(1)在上述解题过程中,从哪一步开始出现错误?请写出该步的代号: ______________;

(2)错误的原因为________________________________;

(3)本题正确的解题过程:

根据短文内容用适当的关系代词或副词填空。

     The time l. ________ Elias first met Nelson Mandela was a very difficult period in his life. Mandela was

the black lawyer 2. ________ ________ he went for advice. Mandela was generous with his time, 3.________

_________ Elias was grateful.

     Elias had very little education. The school 4. ________ Elias studied for only two years was three kilometers

away. The reason 5.________ he had to leave was that his family couldn't continue to pay the school fees and

the bus fare. After trying hard, Elias got a job in a gold mine. However, this was a time 6.________ one had

got to have a passbook to live in Johannesburg. Elias didn't have it and worried about whether he would be out

of work.

     The day 7.________ Nelson Mandela helped him was one of his happiest. When Mandela organized the

ANC Youth League, Elias joined it as soon as possible. Mandela said," The last thirty years have seen the greatest

number of laws stopping our rights and progress, until today we have reached a stage 8.________ we have

almost no rights at all. We were put into a position 9.________ ________ we had either to accept we were less

important, or fight the government..." Elias never forgot how kind Mandela was.

甲连续一周到某银行门外尾随去银行存款的多名个体户，伺机用身上藏着的指头粗细的铁棍打伤个体户后行抢，均因附近有值班人员巡逻，未敢下手。后被联防队员当场抓获。对甲的行为应怎样认定和处理( )

A．犯罪中止

B．犯罪未遂

C．犯罪预备

D．犯罪既遂

出口退税审核系统2.0版采用（）作为数据库。

A.oracle11g

B.oracle9i

C.sqlserver2000

D.sybase

一个行业内存在五种基本竞争力量，即潜在进入者、替代品、供方、需方以及行业内现有竞争者。( )