Part 1. writing
1． 看下图，描述图中所示变化情况
2． 分析说明可能导致该变化出现的原因
3． 结论
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1950 1960 1970 1975 1990(year)
Air Pollution 和 Cancer
Part II Reading Comprehension (Skimming 和 Scanning)(15 minutes)
Directions: In this part, you will have 15 minutes to go over the passage quickly 和 answer the questions on Answer Sheet 1.
For questions 1-7, mark
Y (for YES ) if the statement agrees with the information given in the passage;
N (for NO ) if the statement contradicts the information given in the passage;
NG (for NOT GIVEN) if the information is not given in the passage.
For questions 8-I0, complete the sentences with the information given in the passage.
Robot Cars to Do Battle in Desert Race
When 15 competitors lined up in Nevada last year for the U.S. Defense Department’s first million-dollar robot race, hopes were high. The challenge: to drive a vehicle without a human driver or remote control some 150 miles (241 kilometers) through the Mojave Desert.
But those hopes quickly went up in a cloud of dust as most robots barely managed to get off the starting line. The best performer, a modified Humvee built by engineers at Pennsylvania’s Carnegie Mellon University, traveled 7 miles (11 kilometers ) before breaking down.
To robot devotees(热爱者), however, it was a minor hiccup.
No surprise, then, that 43 teams showed up to try out for this year’s race, dubbed (被称作) the Gr和 Challenge. For the past week, teams ranging from garage enthusiasts to well-funded university engineers have been fine-tuning their machines at qualifying rounds here at the California Speedway in Fontana, California. (Watch the robots in action in our exclusive video. )
Twenty-three finalists were announced Thursday for Saturday’s Gr和 Challenge. The 175-mile (282-kilometer) course starts 和 finishes in Primm, Nevada.
The race promises to be even tougher than last year’s run. But 18 months is an eternity in the robotics world, 和 the technology has vastly improved.
Organizers believe several teams have a real shot of finishing the race in less than ten hours to earn the gr和 prize of two million U.S. dollars.
"When the first team out of the chute (斜道)--Mojavaton, a small team out of Colorado --made it successfully around the 2.2-mile (3.5-kilometer) qualification course, I knew right there 和 then that we had something special," said Ron Kurjanowicz, the chief of staff for the Pentagon’s Defense Advanced Research Projects Agency (DARPA), which is sponsoring the race.
Unknown Course
The aim of the Gr和 Challenge, Defense Department officials say, is to spur development of autonomous ground vehicles that can operate in dangerous environments, such as war zones, keeping soldiers out of harm’s way.
A U.S. Congress m和ate (训令) requires that one-third of military ground vehicles drive themselves by 2015, but the technology to meet that m和ate does not yet exist.
So the government looked to enterprising teams to develop the technology for driverless vehicles, sweetening its offer with the two-million-dollar purse.
None of the 23 teams knows what lies ahead for this year’s race. DARPA won’t reveal the exact route until two hours before the start of the race on Saturday.
But the obstacles on the Fontana qualification course-including a steel--enforced tunnel that wipes out a vehicle’s global positioning system--are made to resemble the rugged, real-life conditions that the vehicles will have to navigate.
The vehicles use sensors such as lasers, cameras, 和 radar to help them avoid obstacles such as rocks 和 cliffs. The computer’s brain has to figure out how to resolve unexpected conflicts, like a boulder sitting in the middle of the road.
"Think about all the decisions that you 和 I have to make when we drive from our house to the store," Kurjanowicz said. "These vehicles have to do the same thing, without a driver."
Among the top contenders in Saturday’s race is TerraMax, a massive truck originally built by the Wisconsin-based Oshkosh Truck Corporation for the U.S. Marine Corps.
In last year’s race, TerraMax managed to go only 1.2 miles (2 kilometers ). Team leader Gary Schmiedel expects to do much better this year. He pointed to the new all-wheel steering feature on the truck as an important addition.
"We can move this large, 15-ton (13.5-metric ton) payload vehicle in a turn that’s equivalent to that of a Humvee," he said.
Ghostrider
The resources of teams like TerraMax or Carnegie Mellon University, which has two vehicles in the race this year, are a far cry from those of some of the other competitors, including inventors, electricians, 和 even a high school team.
One entry, from a Southern California team of engineers, racers, 和 hot-fodders, is called It Came From the Garage. It has a beer keg (小桶) stuck on the back 和 an on-off switch that says "brain."
"Most of the schools 和 organizations we’re up against are just accessorizing conventional vehicles," said team leader Chris "C.J." Pedersen, a former actor. "Our I vehicle I is a custom-built, 21st-century hot rod.., complete with hood scoop 和 exhaust coming off the side."
Anthony Lev和owski, a robotics builder from Berkeley, California, is back with Ghostrider, the only motorcycle robot in the qualifications. Studded with sensors 和 computers, it toppled ( 翻倒) over after 3 feet ( l meter) in last year’s race.
Lev和owski, who had to postpone his graduate studies when he couldn’t find a faculty advisor who believed it would be possible to build the motorcycle robot, says his vehicle has some distinct advantages.
"We’re smaller 和 go a lot more places," he said while tinkering with the robot before another trial run. "We’re also a lot less expensive. This bike costs as much as a tire or a wheel of some of these other guys’ machines."
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