Believe it or not，optical illusion can cut highway crashes.
Japan is a case in point．It has reduced automobile crashes on some roads by Rearly 75 percent using a simple optical illusion．Butst．ripes,called chevrons(人字形)，painted on ther rads make drivers think that they are driving faster than they really are，and thus drivers slow down.
Now the American Automobile Association Foundation for Traffic Safety in Washington D．C. is planning t。repeat Japan’s success．Starting next year，the foundati。n will paint cheyrons and。ther pattems of stripes on selected roads around the country to test how well the patterns reduce highway erashes．
Excessive(too great)speed plays a major role in as much as one fifth of all fatal traffic accidents， according to the foundation．To help reduce those accidents，the foundation will conduct its tests in areas where speed-related hazards(danger)are the greatest curves，exit slopes，traffic circles，and bridges．
Some studies suggest that straight，horizontal bars painted across roads can initially cut the average speed of drivers in half．However,traffic。ften returns to full speed within months as driVers become used to seeing the painted bars．
Chevrons，scientists say，not only give drivers the impression that they are driving faster than they reallv are but als0 make a lane appear to be narrower．The result is a longer lasting reduction in highway speed and the number of traffic accidents．

On roads painted with chevrons，drivers tend to feel that______.

A．thev should avoid speed．related hazards
B. they are driving in the wrong lane
C. they should slow down their speed
D. they are coming near to the speed limit

某班级学生《C++程序设计》成绩表如下图所示。若学生作业成绩、上机成绩和比赛成绩分别占综合成绩的15%、25%和60%，那么可先在E3单元格中输入（1），再向垂直方向拖动填充柄至E10单元格，则可自动算出这些学生的综合成绩。若要将及格和不及格的人数统计结果显示在B11和E11单元格中，则应在B11和E11中分别填写（2）。

空白（2）处应选择（）

A.=COUNT（E3：E10，>=60）和=COUNT（E3：E10，<60）

B.=COUNT（E3：E10，">=60"和=COUNT（E3：E10，"<60"）

C.=COUNTIF（E3：E10，>=60）和=COUNTIF（E3：E10，<60）

D.=COUNTIF（E3：E10，">=60"）和=COUNTIF（E3：E10，"<60"）