问题 选择题

下列措施中,能使蒸发减慢的是(  )

A.将湿衣服展开后晾在向阳、通风处

B.用笤帚把地上的水向周围扫开

C.用保鲜袋装蔬菜放入冰箱

D.用电吹风机吹头发

答案

A、湿衣服放在通风向阳处可以升高液体的温度和加快液体表面的空气流动速度,故加快蒸发,不符合题意;

B、把地上的水散开可以增大液体的表面积,故加快蒸发,不符合题意;

C、用塑料袋包装蔬菜并放入冰箱冷藏室可以降低液体的温度和减慢液体表面的空气流动速度,故可以减慢蒸发,符合题意;

D、使用电风扇吹风可以加快液体表面的空气流动速度,故加快蒸发,不符合题意;

故选C.

单项选择题
阅读理解

KANDAHAR, Afghanistan–-- Afghans burned tires and chanted “Death to America” after U.S troops fired Monday(April 12, 2010) on a civilian bus near Kandahar, killing four people and wounding more than a dozen. Afghanistan’s president accused NATO of breaking its commitment to safeguard civilian lives.

The attack angered Afghan officials and the public in Kandahar, the Taliban’s birthplace, and dealt a blow to U.S and NATO efforts to win popular support for a coming offensive to drive the insurgents(叛乱分子) from the biggest city in the south. NATO expressed regret for the loss of civilian lives and said it was investigating.

Nearly 200 Afghans blocked highway where the shooting occurred, burning tires, firing weapons and chanting “Death to America” and other slogans. They also called for the ouster (forcing somebody out of a pasition) of Afghan President Hamid Karzai, a Kandahar native who has been appealing for the people here to support the U.S-led campaign against the Taliban.

“The Americans are constantly killing our civilians and the government is not demanding an explanation,” protester Mohammad Razaq said. “We demand justice from the Karzai government and the punishment of those soldiers responsible.”

Kandahar, a city of about a half million people, is nominally under government control, but the Taliban have stepped up infiltration(浸润), staging attacks and threatening local people.

“These foreigners have their enemies, but killing Afghans is not the answer,” said Abdul Hadi, who sells homemade herbal medicine in a public market. He said international forces should publish a schedule of their patrols(巡逻) so Afghans can keep out of the way.

“Better yet, I would like to see them leave Afghanistan,” he added.

Haji Zahir, who runs a transport firm, said it was time for U.S. and other foreign forces to withdraw from the country.

“They say they want to bring security. It is all lies, lies. They kill Afghans. That is not the way to bring security,” Zahir said.

46.According to the passage, we can safely conclude that____________.

A.American soldiers are killing Talibans effectively

B.Anger rises as US troops kill 4 Afghans on a bus

C.NATO expressed great dissatisfaction with American troops

D.Afghan President Hamid Karzai required NATO to withdraw

47.The underlined word in Paragraph 5 nominally most probably means____________.

A.completely unknown to the people in the world

B.partially well-known to the people across the globe

C.bearing the name of a famous person around the world

D.officially described as something, when this is not really true

48.As for NATO soldiers’ rude action, Abdul Hadi is ____________.

A.absolutely angry and upset        B.a little pleased but impatient

C.very angry and dissatisfied        D.impatient but bearable

49.We can infer from the passage that____________

A.NATO troops can completely control Afghanistan

B.NATO troops can bring security to Afghanistan

C.Afghans will accept NATO’s control sooner or later

D.it’s impossible for NATO to conquer Afghanistan and its people

50.Which statement is true according to the passage?

A.NATO fails to win popular support for a coming offensive.

B.Kandahar is the most important city in Afghanistan.

C.NATO has really brought security to Afghanistan.

D.NATO troops will withdraw from Afghanistan in the near future.