问题 选择题

兴奋剂检测是对运动员的一项重要检测.其中一种兴奋剂的化学式为C20H26O2,下列关于兴奋剂的说法正确的是(  )

A.该兴奋剂属于氧化物

B.该兴奋剂是由48个原子构成的

C.该兴奋剂是由碳、氢、氧三种元素组成的

D.该兴奋剂中碳、氢、氧三种元素的质量比为10:13:8

答案

A、由兴奋剂的化学式为C20H26O2,该物质是由三种元素组成,而氧化物是由两种元素组成,则不属于氧化物,故A错误;

B、由兴奋剂的化学式为C20H26O2,则1个分子中含有20+26+2=48个原子,而物质不是由原子构成的,故B错误;

C、由兴奋剂的化学式为C20H26O2,该物质是由碳、氢、氧三种元素组成,故C正确;

D、由兴奋剂的化学式为C20H26O2,则碳、氢、氧三种元素的质量比为12×20:1×26:16×2=120:13:16,故D错误;

故选C.

阅读理解

     Motorists who used to listen to the radio or their favorite tunes on CDs may have a new way to

entertain themselves, after engineers in Japan developed a musical road surface.

     A team from the Hokkaido Industrial Research Institute has built a number of "melody roads",  

which use cars as tuning forks(音叉)to play music as they travel.

     The concept works by using grooves(凹槽). They are cut at very specific intervals in the road

surface. The melody road uses the spaces between to create different notes.

     Depending on how far apart the grooves are, a car moving over them will produce a series of high

or low notes, and designers are able to create a distinct tune.

     Patent documents for the design describe it as notches(刻痕)"formed in a road surface so as to play

a melody without producing simple sound or rhythm and reproduce melodylike tones".

     There are three musical strips in central and northern Japan-one of which plays the tune of a Japanese

pop song. Reports say the system was invented by Shizuo Shinoda. He scraped some markings into a

road with a bulldozer(推土机)before driving over them and found that they helped to produce all kinds

of tones.

     The optimal speed for melody road is 44 kph, but people say it is not always easy to get the

intended sound.

     "You need to keep the car windows closed to hear well," wrote one Japanese blogger. "Driving too

fast will sound like playing fast forward, while driving around 12 mph[20 km/h]has a slowmotion effect,

making you almost carsick."

1. According to the passage, melody roads use________to create different notes.

A. cars  

B. grooves

C. spaces between intervals  

D. bulldozers

2. We can learn from the passage that the highness of notes is depended on________.

A. how far the grooves are

B. how big the grooves are

C. the number of the grooves

D. the speed of the car

3. The underlined word "optimal" in the passage might mean________.

A. fastest  

B. possible

C. best  

D. suitable

4. In order to hear the music well, you have to________.

A. drive very fast

B. drive slowly

C. open the windows wide

D. keep the windows closed

5. What's the best title of the passage?

A. A New Type of Music

B. Melody Roads in Japan

C. A Musical Road Surface

D. A New Invention in Japan

问答题 简答题