问题 选择题

2009年4月22日,厦门--台湾海上客运直航开始了首航之旅.台湾客货混装船“台华”轮载着旅客从厦门出发航行7小时后抵达澎湖,停留一夜后,再航行3小时左右抵达高雄,全程307千米.不考虑停留时间,下列说法中正确的是(  )

A.“台华”轮的行驶平均速度为30.7m/s

B.“台华”轮的行驶平均速度为30.7km/h

C.“台华”轮的行驶最大速度为30.7m/s

D.“台华”轮的行驶速度为30.7m/s

答案

“台华”轮的行驶路程s=307km,行驶时间t=7h+3h=10h,

“台华”轮在航行过程中的行驶平均速度为

v=

s
t
=
307km
10h
=30.7km/h≈8.53m/s,故选项A错误,B正确;

平均速度为30.7km/h,它不是行驶的最大速度,故C错误;

又因为“台华”轮做变速运动,所以求出的是平均速度,不是行驶速度,故D错误.

故选B

阅读理解

It’s 2035. You have a job, a family and you’re about 40 years old. Welcome to your future life.     Getting ready for work, you pause in front of the mirror, “Turn red,” you say. Your shirt changes from sky blue to deep red. Tiny preprogrammed electronic(智能电子元件) is rearranged in your shirt to change its color. Looking into the mirror, you find it hard to believe that you are 40. You look much younger. With amazing advances in medicine, people in your generation may live to be 150 years old. You’re not even middle-aged.

As you go into the kitchen and prepare to pour your breakfast cereal into a bowl, you hear: “To lose weight, you shouldn’t eat that,” from your shoes. They read the tiny electronic code(电 子源码)on the cereal box to find out the nutrition details. You decide to listen to your shoes. “Kitchen, what can I have for breakfast?” A list of possible food appears on the counter as kitchen checks its food supplies.

“Ready for your trip to space?” you ask your son and daughter. In 2005 only specially trained astronauts went into space—and very few of them. Today anyone can go to space for day trip or longer vacation. Your best friend even works in space. Handing your children three strawberries each, you add, “The doctor said you need these for space travel.” Thanks to medical advice, vaccination shots(防疫针) are a thing of the past. Ordinary foods contain specific vaccines. With the berries in their mouths, the kids head for the front door.

It’s time for you to go to work. Your car checks your fingerprints and unlocks the doors. “My office. Autopilot,” you command. Your car drives itself down the road and moves smoothly into traffic on the highway. You sit back and unroll your e-newspaper. The latest news downloads and fills the viewer. Looking through the pages, you watch the news as video films rather than read it.

小题1: What changes the color of your shirt?

A.The mirror.

B.The shirt itself.

C.The counter.

D.The medicine.小题2: How do the shoes know that you shouldn’t eat the breakfast cereal?

A.By pouring the breakfast into a bowl.

B.By listening to the doctor’s advice.

C.By testing the food supplies in the kitchen.

D.By checking the nutrition details of the food.小题3: The strawberries the children eat serve as ______.

A.breakfast

B.lunch

C.vaccines

D.nutrition小题4: How is the text organized?

A.In order of time

B.In order of frequency.

C.In order of preference(偏爱).

D.In order of importance

单项选择题