长期以来,我国一直采取大力发展大城市,形成城市群以带动周边城市的发展模型。()
查看答案
Who is Sir George Cayley?
A. Pioneer in aviation
B. Famous theorist
What are the four forces identified by Cayley?
A. weight
B. drag
C. lift
D. thrust
Who is Charles Green
A. a politician
B. a balloonist
What happened to Le Giant?
A. crashed
B. successfully landed