问题 单项选择题

由气溶胶的辐射特性引起的冷却作用类似于遮阳伞,故称为“阳伞效应”。悬浮在大气中的气溶胶颗粒一方面将部分太阳入射辐射反射回宇宙空间,削弱了到达地面的太阳辐射能,增加行星反照率,使地面接收的太阳能减少;另一方面某些吸湿性的粒子又作为凝结核,促使周围水汽在它上面凝结,导致低云、雾的增多,改变云的光学特征和寿命,使云的反照率增加,同样具有减少入射辐射,使地面和底层大气的温度降低的作用。“阳伞效应”在北半球表现得最为明显,其原因在于本地区较高的工业化程度和由此产生的空气污染。
对这段文字理解不准确的是( )。

A.气溶胶因其辐射特性能产生的“阳伞效应”
B.大气中的气溶胶具有很强的吸湿性
C.气溶胶能极大地防止太阳对地球的辐射
D.空气污染物能增强“阳伞效应”

答案

参考答案:B

解析: 原文着重介绍了气溶胶能够引起“阳伞效应”的原因,并通过现实事例进行了说明。选项B的错误在于,文中只提到气溶胶中存在某些吸湿性因子,并没有说气溶胶具备很强的吸湿性。

单项选择题

第1篇 Road Trip Vacations


It’s summer. In the United States, it’s the season of swimming pools, barbeques, camping and road trips.
Road trip vacations where the car journey is part of the fun are especially popular with college students, who like to explore the country on wheels. These budget trips are ideal for students who often have plenty of free time but little money.
"Ever since I went to college, I’ve been traveling around a lot, exploring the country," said Austin Hawkins, a 19-year-old college student from New York. This summer, Hawkins and his friends have spent weekends traveling in New England.
The best part about car trips, said Hawkins, is that you can be spontaneous. "On a road trip, if you get interested in things you see along the way you can stop and explore. "
Matt Roberts, a 20-year-old student from Ohio who drove to Montreal, Canada, agrees. "With road trips you don’t have to plan in advance, you can just get into a car and drive. "
Even with high gas prices, driving with friends is cheaper than flying. Roberts paid about 40 dollars for gas, but a round trip plane ticket would have cost nearly 400 dollars.
Driving trips first became popular in the 1920s. Newly paved roads and improved cars made it possible to travel longer distances. Motels started appearing outside cities.
By the 1950s, car ownership became the norm. Construction of the US interstate highway system began in 1956 and motel and restaurant chains popped up everywhere making long distance trips easier.
Today, the US has the highest car ownership rate in the world. Only 8 percent of American homes have no car, according to the most recent US census.
Though many college students don’t own a car, most have access to one. On many of Hawkins’ trips, they used a borrowed van.
Hawkins’ most memorable road trip took place over spring break. He and two friends drove from New York to New Orleans to volunteer, helping rebuild the city after Hurricane Katrina hit it last July. They crossed the country in two days and slept in their car in church parking lots.
Roberts’ road trip to Canada last winter was even more eventful. Upon arriving in Montreal, they were lost in a blizzard and shivering in the -25~cold. To find their hotel, they turned on a laptop and drove around in circles until they found a spot with wireless Internet coverage.
"I know we should have planned better, but we’re young. Now, when I see those guys I always say: ’Remember when we were lost in the snow storm! ’ I’ll never forget that. \

What will Hawkins do when he sees something interesting on a road trip

A.He will turn back.

B.He will drive around.

C.He will stop to explore.

D.He will stop explorin

单项选择题