单项选择题
Jet belts and rocket belts were developed ______.
A.20-30 years ago
B.50 years ago
C.recently
D.30 years ago
点击查看答案&解析
<上一题
目录
下一题>
热门
试题
单项选择题
An analogy was used to compare the way one could fly in the Solo Flyer to ______.
A.how a helicopter flies
B.how the Jetsons fly
C.how the airphibian flies
D.how Superman flies
点击查看答案&解析
单项选择题
The Solo Flyer is able to lift off the ground by using ______.
A.a solar powered engine
B.engine-powered twin fans
C.large flapping wings
D.rotating blades
点击查看答案&解析
相关试题
26()
27()
28()
30()
29()