问题 填空题

投掷一枚质地均匀的正方体骰子两次,第一次出现向上的点数为a,第二次出现向上的点数为b,直线l1的方程为ax-by-3=0,直线l2的方程为x-2y-2=0,则直线l1与直线l2有交点的概率为________.

答案

投掷一枚质地均匀的正方体骰子两次,向上的点数的结果有36种情况:(1,1),(1,2),…,(6,6),直线l1与直线l2有交点即两直线斜率不相等,b≠2a,所以除(1,2),(2,4),(3,6)这3种情况外,其余都符合题意,即直线l1与直线l2有交点的情况有33种,故所求概率为

阅读理解

阅读短文,并按要求完成76~80题。

As the Internet becomes more popular, many older media (媒体) businesses are dying out. But TV seems to be doing OK. In fact, it's doing better than OK. Though the Internet is popular in the world, television continues to draw more and more people all over the world to many of its programs. Hundreds of millions turn to TV to watch World Cup soccer,Olympic Games and Discoveries.

In many places, increasing numbers of people can watch more TV than before. Ten years ago, only 44% of British homes had satellite or cable TV(卫星或有线电视).Today, more than 93% do. More importantly, recent studies show that people are spending more time watching TV. Surprisingly, this is even true of young people between the ages of 8 and 18.Today's television industry has given so many choices. As a result, people can watch more of the things they like 24 hours a day.

The technology behind television has also improved. The big boxes that once filled living rooms are gone. Today's TV screens are thinner and thinner, yet the pictures are better and better. TVs are also moving from living rooms into kitchens and vehicles.

For years, TVs have also been used as video game players. But now they have been used in a few new ways. Many televisions can connect to the Internet and record programs. They also let people watch two programs at the same time. Today the most modern television has been on the way of development.

The Internet is the main challenge (挑战) for television now. But TV industry has shown that television will be important for years to come.

【1】判断正误(“T”表示正确,“F”表示错误);【2】完成句子;【3】~【4】简略回答问题;【5】将文中画线句子译成汉语。

小题1:Studies show that people are spending more time watching TV than before. 【   】

小题2: Many televisions can _______________________ the Internet and record programs.

小题3:Where are TVs moving from living rooms?

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小题4: What is the main challenge for television?

____________________________________________________________________

小题5:____________________________________________________________________

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