Birds can transform the shape of their wings by fanning out their feathers or moving them closer together. Those adjustments allow birds to cut through the sky more flexibly than rigid drones (无人机). Now, using new insights into exactly how pigeons ‘joints control the spread of their wing feathers, researchers have built a robotic pigeon. This research paves the way for creating more light aircraft, says Dario Floreano, a roboticist in Switzerland not involved in the work.

“What’s really cool about this robot is that you can make adjustments in a robotic wing that you could never do when studying flight in a bird”, says David Lentink, an engineer and biologist at Stanford University. A controllable robotic pigeon solves that problem. In flight tests, Lentink’s team observed that bending only the fingers of one wing eased the robot into a banked turn-offering the first evidence that birds may sometimes use just their fingers to direct in flight. In a second study, Lentink’s group used their robotic wing design to confirm another insight into bird flight: how gaps are prevented from forming between feathers on extended wings.

This is the best set of robotic wings yet for testing how birds adjust their flight feathers to move through the air, says Tyson Hedrick, a biomechanist. But “there’s plenty of room for improvement.” For instance, a future flying robot could include a shoulder joint to investigate how waving a bird’s wings up and down influences flight, he says.

【1】What is the newly-found worth of pigeons?

A.They help study other species.

B.They protect other urban birds.

C.They provide proof of mice’s harm.

D.They inspire a new aircraft.

【2】What is Dario Floreano’s attitude to the research?

A.Negative.B.Positive.

C.Neutral.D.Critical.

【3】What do the underlined words “that problem” in paragraph 3 refer to?

A.Pigeons in flight can hardly be observed.

B.People can’t make adjustments in birds’ wings.

C.It is difficult for pigeons to make a banked turn.

D.Pigeons fail to control the spread of their wing feathers.

【4】Where does the text probably come from?

A.A travel journal.

B.A travel brochure.

C.A science fiction.

D.A science magazine.

【题目】

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Frequently Asked Questions

What is “UNICEF”?

UNICEF is the United Nations Children’s Fund

When created in 1946 to help children in war-torn Europe, China and the Middle East, UNICEF stood for “United Nations International Children’s Emergency Fund”. In 1947, UNICEF USA was founded, one year after UNICEF, to support UNICEF’s lifesaving work for children.

By 1953, UNICEF's task was extended to address the needs of children in the developing world. At that time, the words “international” and “emergency” were dropped from the organization’s name, making it simply the United Nations Children’s Fund. UNICEF has helped save more children’s lives than any other humanitarian organization.

What is UNICEF USA’s mission?

We work for the survival, protection and development of children worldwide through fund raising, advocacy and education.

How can I volunteer for UNICEF in the field?

UNICEF secures volunteers, who must have at least a Bachelor’s Degree and two-to-five years’ experience in their field of expert knowledge and skills, through the United Nations Volunteers program.

If you are a citizen of the United States and meet the above standards, send your resume to the United Nations Volunteers program at the following address for more information: United Nations Volunteers, c/o Peace Corps, 1111 20th St.N.W, Washington, DC 20526.

If you are interested in volunteering within the United States, click here to learn how.

May I donate non-cash goods for emergency relief?

Some have asked us about donating goods here in the U.S. for emergency relief efforts abroad. While we are grateful for the desire to help, UNICEF does not accept non-cash goods. Why?

Financial donations are the fastest and most efficient way to provide assistance. Donated goods must be screened, sorted, stored and transported. UNICEF pre-positions supplies to speed up delivery and sources them locally whenever possible. A blanket donated today can take weeks, or even months, to arrive abroad. A dollar donated today, however, will be arranged tomorrow to buy lifesaving supplies.

We also purchase supplies in large quantities to save money. That means your financial donation will get more supplies to more kids in need than your donation of non-cash goods.

【1】Which of the following statements is true of UNICEF USA?

A.It no longer provides emergency fund.

B.It is localized to focus on national affairs.

C.It was originally created for kids’ education.

D.It supports children growth at home and abroad.

【2】If you want to be a UNICEF USA volunteer,______ is NOT a must.

A.required education backgroundB.related working experience

C.American nationalityD.educational program participation

【3】Financial donation is a better choice than non-cash goods because of_________.

A.the good willB.operational efficiency

C.local assistanceD.the reliable supply

—Not really, just a nodding ______.

A. acquaintance B. administration

C. consequence D.consideration

A. even if B. whether C. no matter D. however

A. them B. which C. it D. what

A. which B. when C. where D. that

A. can’t have left B. may not have left

C. shouldn’t have left D. mustn’t have left

A. would take B. took

C. had taken D. were taking

A. goes by B. goes against C. goes with D. goes on

A. on B. in C. at D. about