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问题 填空题

下列四个命题：

（1）函数f（x）在x≥0时是增函数，x≤0也是增函数，所以f（x）在R上是增函数；

（2）若二次函数f（x）=ax2+bx+2没有零点，则b2-8a＜0且a≠0；

（3） y=x2-2|x|-3的递增区间为[1，+∞）；

（4） 若f（-2）=f（2），则定义在R上的函数f（x）不是奇函数．其中正确的命题是 ______．

答案

对于（3），因为 y=x2-2|x|-3是偶函数，其定义域关于原点对称，其单调区间也关于原点对称，所以递增区间应有两个，是[1，+∞）和（-∞，-1]，故（3）错

对于（4），取f（x）=

x-2      x＞0
-x+2      x＜0
，满足f（-2）=f（2），但f（x）是奇函数，故（4）错

故答案为：（1）（2）

填空题

How did the Olympic Games start In ancient Greece athletic festivals were very important and had p ________ (1). Originally the Festival was held in honour of .Zeus, the supreme god in Greek Mythology. Eventually the Olympian athletic festival had lost its ________ (2) and became an international event. No one knows exactly ________ (3) the Olympic Games go, but some scholars recorded date from 776 B.C.According to some scholars, at first the only Olympic event was ________ (4), called a stadium and that was the only event until 724 B.C. After that, other ________ (5) were added and sixteen years later in ________ (6) the pentathlon was added and wrestling became part of the games. This pentathlon was a five-event match which ________ (7) running, wrestling, leaping, throwing the discus, and hurling the javelin.The games were held ________ (8) and after an uninterrupted history of 1170 years, the games ________ (9) in A.D. 394, the Christian era, because of their pagan origin.It was over ________ (10) before there was another such international athletics gathering. In 1896, the first of the modern ________ (11) opened in Athens, Greece.Nowadays, the Games are held in different countries ________ (12). The host country provides vast facilities such as stadiums and ________ (13).Many more sports are represented, including the very celebrated event: ________ (14).The Olympics start with the arrival in the stadium of a torch, ________ (15) on Mount Olympus by the sun’s rays. The torch is carried by ________ (16) to the stadium. The Olympic flame symbolizes the ________ (17) of the ancient Greek athletic ideals, and it burns throughout the Games until ________ (18). The well-known Olympic flag, however, is ________ (19): the five interlocking rings symbolize the uniting of all five continents ________ (20).
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选择题

The two countries            with each other because of the incident on the border.     [ ]

A. came into conflict          

B. came into a conflict    

C. came to conflicts            

D. came into conflicts
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