Petrochemicals are chemicals made from the _____ found in petroleum.
A. hydrocarbons
B. electromagnet
C. areospace
D. chromolithograph
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He specialize in aeronautics. It is a science of ______.
A. aerolith
B. sailing across the ocean
C. flying in airship
D. the flow of air
Hydrobiplane is a kind of plane which has ______.
A. two wings and flies in space
B. two wings and flies above water
C. four wings and flies above water
D. four wings and flies in space
Mr. Wilson keeps a shop for selling flowers. We call him a _____.
A. flora
B. grocery
C. florist
D. greengrocer
An astronaut is a person who travels through space in a _____.
A. warship
B. airship
C. steamship
D. spaceship
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