相关试题
共用题干
Wide World of Robots
Engineers who build and program robots have fascinating jobs. These researchers tinker（修补）with ma-
chines in the lab and write computer software to control these devices."They're the best toys out there,"
says Howie Choset at Carnegie Mellon University in Pittsburgh.Choset is a roboticist,a person who designs,
builds or programs robots.
When Choset was a kid,he was interested in anything that moved-cars,trains,animals.He put motors
on Tinkertoy cars to make them move.Later,in high school,he built mobile robots similar to small cars.
Hoping to continue working on robots,he studied computer science in college.But when he got to
graduate school at the California Institute of Technology in Pasadena,Choset's labmates were working on
something even cooler than remotely controlled cars:robotic snakes.Some robots can move only forward,
backward , left and right. But snakes can twist（扭曲）in many directions and travel over a lot of different
types of terrain（地形）."Snakes are far more interesting than the cars,"Choset concluded.
After he started working at Carnegie Mellon,Choset and his colleagues there began developing their own
snake robots.Choset'5 team programnied robots to perform the same movements as real snakes,such as
sliding and inching forward.The robots also moved in ways that snakes usually don't,such as rolling.
Choset's snake robots could crawl（爬行）through the grass ,swim in a pond and even climb a flagpole.
But Choset wondered if his snakes might be useful for medicine as well. For some heart surgeries,the
doctor has to open a patient' s chest ,cutting through the breastbone. Recovering from these surgeries can be
very painful. What if the doctor could perform the operation by instead making a small hole in the body and
sending in a thin robotic snake?
Choset teamed up with Marco Zenati,a heart surgeon now at Harvard Medical School ,to investigate the
idea. Zenati practiced using the robot on a plastic model of the chest and they tested the robot in pigs.
A company called Medrobotics in Boston is now adapting the technology for surgeries on people.
Even after 15 years of working with his team's creations,"I still don't get bored of watching the motion
of my robots,"Choset says.
Choset's snake robots could make more movements than the ones others developed.
A: Right
B: Wrong
C: Not mentioned
共用题干
The Weight Experiment
Nicola Walters has been taking part in experiments in Scotland to discover why humans gain and lose weight. Being locked in a small room called a“ calorimeter”（热量测量室）is one way to find out.
1 .The signs above the two rooms read simply“Chamber One”and“Chamber Two”.These are the calorimeters:4m by 2m white-walled rooms where human volunteers are locked up in the name of science .Outside these rooms another sign reads“Please do not enter work in progress” and in front of the rooms advanced machinery registers every move the volunteers make.Each day,meals measured to the last gram are passed through a hole in the wall of the calorimeter to the resident volunteer.
2 .Nicola Walters is one of twenty volunteers who,over the past eight months,have spent varying periods inside the calorimeter. Tall and slim,Nicola does not have a weight problem,but thought the strict diet might help with her training and fitness programme.As a self-employed community dance rorker,she was able to fit the experiment in around her work.She saw an advert for volun- teers at her local gym and as she is interested in the whole area of diet and exercise,she thought she would help out.
3. The experiment on Nicola involved her spending one day on a fixed diet at home and the next in the room.This sequence was repeated four times over six weeks.She arrived at the calorimeter at8:30 am on each of the four mornings and from then on everything she ate or drank was carefull) measured .Her every move was noted too,her daily exercise routine,timed to the last second. At regular intervals,after eating,she filled in forms about how hungry she felt and samples were taken for analysis.
4 .The scientists help volunteers impose a kind of order on the long days they face in the room. “The first time,I only took one video and a book,but it was OK because I watched TV the rest of the time,”says Nicola. And twice a day she used the exercise bike. She pedaled（踩踏板） for half an hour,watched by researchers to make sure she didn't go too fast.
5 .It seems that some foods encourage you to eat more,while others satisfy you quickly.Volunteers are already showing that high-fat diets are less likely to make you feel full.Believing that they may now know what encourages people to overeat,the researchers are about to start testing a high-protein weight-loss diet. Volunteers are required and Nicola has signed up for further sessions.
Volunteers have to get prepared for the time in the calorimeter_________.
A: the volunteers do
B:.because she does not have a weight problem
C: because the life there can be very boring
D: make people overeat
E: because she was her own boss
F: after passing a high-protein test
共用题干
Please Fasten Your Seatbelts
Severe turbulence（湍流）can kill aircraft passengers. Now,in test flights over the Rocky
Mountains , NASA（美国航空航天局）engineers have successfully detected clear-air turbulence up to 10 seconds before an aircraft hits it.
Clear-air turbulence often catches pilots by surprise.Invisible to radar,it is difficult to forecast and can hurl（用力抛出去）passengers about the cabin. In December 1 997 , one passenger died and a hundred others were injured when unexpected rough air caused a United Airlines flight over the Pacific to drop 300 meters in a few seconds.
However,passengers can avoid serious injury by fastening their seatbelts.“It is the only antidote（对策）for this sort of thing,”says Rod Bogue,project manager at NASA's Dryden Flight
Research Center in Edwards,California.
The centre's new turbulence detector is based on lidar,or laser radar. Laser pulses are sent ahead of the plane and these are then reflected back by particles in the air. The technique depends on the Doppler effect.The wavelength of the light shifts according to the speed at which the particles are approaching. In calm air,the speed equals the plane's airspeed.But as the particles swirl（打漩）in rough air,their speed of approach increases or decreases rapidly .The rate of change in speed corresponds to the severity（激烈程度）of the turbulence.
In a series of tests that began last month,a research jet flew repeatedly into disturbed air over the mountain ridges（山脉）near Pueblo , Colorado. The lidar detector spotted turbulence between 3 and 8 kilometers ahead,and its forecasts of strength and duration corresponded closely with the turbulence that the plane encountered.
Bogue says that he had“a comfortable amount of time”to fasten his seatbelt. The researchers are planning to improve the lidar's range with a more powerful beam.The system could be installed on commercial aircraft in the next few years.
The last paragraph tells us,among other things,that_______.
A: the lidar detector needs improvement
B: many airlines are interested in the system
C: passengers often forget to fasten their seatbelts
D: the lidar detector can be used in a wide range of areas
共用题干
Wide World of Robots
Engineers who build and program robots have fascinating jobs. These researchers tinker（修补）with ma-
chines in the lab and write computer software to control these devices."They're the best toys out there,"
says Howie Choset at Carnegie Mellon University in Pittsburgh.Choset is a roboticist,a person who designs,
builds or programs robots.
When Choset was a kid,he was interested in anything that moved-cars,trains,animals.He put motors
on Tinkertoy cars to make them move.Later,in high school,he built mobile robots similar to small cars.
Hoping to continue working on robots,he studied computer science in college.But when he got to
graduate school at the California Institute of Technology in Pasadena,Choset's labmates were working on
something even cooler than remotely controlled cars:robotic snakes.Some robots can move only forward,
backward , left and right. But snakes can twist（扭曲）in many directions and travel over a lot of different
types of terrain（地形）."Snakes are far more interesting than the cars,"Choset concluded.
After he started working at Carnegie Mellon,Choset and his colleagues there began developing their own
snake robots.Choset'5 team programnied robots to perform the same movements as real snakes,such as
sliding and inching forward.The robots also moved in ways that snakes usually don't,such as rolling.
Choset's snake robots could crawl（爬行）through the grass ,swim in a pond and even climb a flagpole.
But Choset wondered if his snakes might be useful for medicine as well. For some heart surgeries,the
doctor has to open a patient' s chest ,cutting through the breastbone. Recovering from these surgeries can be
very painful. What if the doctor could perform the operation by instead making a small hole in the body and
sending in a thin robotic snake?
Choset teamed up with Marco Zenati,a heart surgeon now at Harvard Medical School ,to investigate the
idea. Zenati practiced using the robot on a plastic model of the chest and they tested the robot in pigs.
A company called Medrobotics in Boston is now adapting the technology for surgeries on people.
Even after 15 years of working with his team's creations,"I still don't get bored of watching the motion
of my robots,"Choset says.
Choset began to build robots in high school.
A: Right
B: Wrong
C: Not mentioned
共用题干
Eastern Quakes can Trigger Big Shakes
In the first week of November 2011,people in central Oklahoma experienced more than two dozen earth-
quakes.The largest,a magnitude（量）5.6 quake,shook thousands of fans in a college football stadium,
caused cracks in a few buildings and scared many people who had never felt a quake before.Oklahoma is not
an area of the country famous for its quakes.If you watch the news on TV,you will see reports about all sorts
of natural disasters.But the most dangerous type of natural disaster,and also the most unpredictable,is the
earthquake.
Researchers at the US Geological Survey(USGS)estimate that several million earthquakes occur globally
each year. That may sound scary,but people don't feel many of them because they happen in remote and
unpopulated regions.Many quakes happen under the ocean,and others have a very small magnitude.
Scientists know about small,remote quakes only because of very sensitive electronic devices called seis-
mometers（地震仪）.These devices detect and measure the size of ground vibrations（震颤）produced by
earthquakes.Altogether,USGS researchers use seismometers to identify and locate about 20,000 earthquakes
each year.
Although earthquakes can happen anywhere in the world,really big quakes occur only in certain areas.
The largest ones register a magnitude 8 or higher and happen,on average,only once each year. Such big
ones typically occur along the edges of Earth ' s tectonic plates（构造板块）.
Tectonic plates are huge pieces of Earth ' s crust（外壳）,sometimes many kilometers thick. Often,
edges of these plates temporarily lock together. When plates push and scrape（擦）past each other earthquakes
occur. On average,tectonic plates move very slowly一about the same speed as your fingernails grow.
But sometimes earthquakes rumble（轰轰作响）through portions of the landscape far from a plate ' s
edges.Although less expected,these"mid-plate"small earthquakes can do substantial damage.Some of the
biggest known examples hit the eastern half of the United States two centuries ago.Today,scientists are still
puzzling over why the quakes occurred and when similar ones might occur.
Big earthquakes of a magnitude 8 or higher seldom happen far from the edges of tectonic plates.
A:Right
B:Wrong
C:Not mentioned
