He decided to devote all his time and effort __ scientific investigation.
A. In
B. On
C. From
D. to
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In most circumstances, a speaker should avoid passing visual aids among the audience?()
He fell in love with her at first __.
A. Scene
B. Sight
C. View
D. look
In most circumstances you should keep your visual aids on display throughout the speech?()
When creating a visual aid, you should keep in mind the size of the room in which you