Aeronaut John Steiner inflates his hot air balloon at Erie, Pennsylvania, as seen in the oldest known photograph of an aircraft, a quarter-plate ambrotype taken in June 1857.
If the balloon sails to the ground pick it up, put it back on the plate and keep on moving.
选两人比，每人手拿一只托盘，在托盘上放上气球。
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A newly developed pipeline plug is composed of a central pipe, balloon, piston, spring, clamp, backplate, inside and outside joints, connecting plate and a wedge key.