The “Spirit” Mars pathfinder from the US has adopted ____ soft landing.
A. Landing leg type
B. Airbag bounce type
C. Aerial crane type
D. Rocket thrust
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Nowadays computer and computer technology has completed ____ of the work in aircraft design and manufacture.
A. More than 50%
B. More than 60%
C. More than 70%
D. More than 80%
CFD could be a substitution of wind tunnel tests under ____.
A. High angle of attack situation
B. Normal wind tunnel tests
C. Separate flow situation
D. Complex flowing control situation
The turbulent drag is ____ to the laminar drag.
A. 2 to 4 times
B. 3 to 5 times
C. 4 to 6 times
D. 5 to 7 times
Which of the following is wrong about the vortex generator? ____.
A. Its shape looks like a small triangular wing panel.
B. Can suppress the airflow separation and reduce the drag.
Can enhance the lift of the wing.
D. Placed on engine nacelles and can suppress the airflow separation of nacelle.
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