问题 填空题

某“AD营养钙奶”产品包装袋上的品名和配料如下:

品名:×××AD营养钙奶

配料:①水  ②蔗糖  ③奶粉④乳酸钙  ⑤柠檬酸⑥维生素A  ⑦维生素D ⑧食用色素  ⑨脂肪

请回答:

(1)该产品中能为人类生命活动提供能量的是(填编号,下同)______;

(2)人体缺少配料表中的______,会引起夜盲症.所以人体摄入营养要均衡;

(3)该产品所含的钙元素属于人体中______(填“常量”或“微量”)元素.

答案

(1)根据提供的物质可以看出,蔗糖属于糖类,奶粉富含蛋白质,脂肪属于油脂,能为人体提供能量,故填:②③⑨;

(2)人体缺乏维生素A会造成夜盲症,故填:⑥;

(3)钙元素属于人体中的常量元素,故填:常量.

单项选择题

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.

The American Automobile Association Foundation for Traffic Safety plans to()

A. try out the Japanese method in certain areas

B. change the road signs across the country

C. replace straight, horizontal bars with chevrons

D. repeat the Japanese road patterns

单项选择题