更多"Both Boeing and Airbus have trumpet"的相关试题:
[单项选择]Both Boeing and Airbus have trumpeted the efficiency of their newest aircraft, the 787 and A350 respectively. Their clever designs and lightweight composites certainly make a difference. But a group of researchers at Stanford University, led by Ilan Kroo, has suggested that airlines could take a more naturalistic approach to cutting jet-fuel use, and it would not require them to buy new aircraft.
The answer, says Dr. Kroo, lies with birds. Since 1914, and a seminal paper by a German researcher called Carl Wieselsberger, scientists have known that birds flying in formation—a V-shape, echelon or otherwise—expend less energy. The air flowing over a bird’s wings curls upwards behind the wingtips, a phenomenon known as upwash. Other birds flying in the upwash experience reduced drag, and spend less energy propelling themselves. Peter Lissaman, an aeronautics expert who was formerly at Caltech and the University of Southern California, has suggested that a formation of 25 birds might en
A. energy cost reduced in a formation of V-shape and echelon or otherwise
B. 25 birds might enjoy 71% less energy consuming
C. a naturalistic airline works well than clever designs and lightweight composites
D. Kroo and his group are opposites who think that buying new aircraft is wasteful
[单项选择]Children whose biological parents both have Tic Syndrome Z (TSZ), which is characterized by the involuntary contraction of certain muscles, are about four times more likely to develop such contractions than are children whose biological parents do not have TSZ. It is likely, therefore, that predisposition to TSZ is an inherited trait.
Which of the following, if true, would most strengthen the conclusion above
A. Children whose parents have TSZ are more likely to develop TSZ if they are under unusual stress at school or at home than if they are not under such stress.
B. Children whose biological parents do not have TSZ are more likely to develop TSZ if they are raised by adoptive parents with TSZ than if they are raised by their biological parents.
C. Children whose biological parents have TSZ are as likely to develop TSZ if they are raised by adoptive parents who do not have TSZ as if they are raised by their biological parents.
D. Children whose biological parents have TSZ and who develop TSZ usually avoid developing a severe form of the syndrome if they seek treatment for TSZ shortly after developing the first signs of it.
E. (E) Children with TSZ whose biological parents do not have TSZ are less likely to have the syndrome diagnosed when symptoms first appear than are children with TSZ whose biological parents have TSZ.
[单项选择]These two areas are similar()they both have a high rainfall during this season.
A. to that
B. besides that
C. in that
D. except that
[单项选择]These two areas are similar ______ they both have a high rainfall during this season.
A. to that
B. beside that
C. in that
D. except that
[简答题]If Alan gives Brenda $5.50, they will both have the same amount of money. If Brenda gives Alan $1.50, Alan will have twice as much as Brenda. What did they have at the start
[单项选择]These two areas are similar( )they both have a high rainfall during this season.
A. to that
B. besides that
C. in that
D. except that
[填空题]经友好协商, both parties have entered into this contract with the following terms and conditions.
[简答题]Both research and practical experience have shown that a ()(均衡的饮食对健康是必不可少的).