The invention relates to a cup. The cup includes a cup, a power plug which is connected with the cup through a wire, and a power socket which is used in cooperation with the power plug; jacks with rightwards-facing through holes, which are arranged symmetrically along a vertical direction, are formed in the power socket; a first change-over slot is formed in each jack; a second change-over slot isformed between the two jacks; the second change-over slot is communicated with the first change-over slots; second toothed joint wheels are arranged in the first change-over slots; the left side andright side of each second toothed joint wheel are symmetrically provided with change-over sleeves, the inner diameter of the change-over sleeves being equal to the diameter of the jacks; the two change-over sleeves are rotatably installed in the left end wall and the right end wall of the corresponding first change-over slot; a spiral hole is formed at the middle of each second toothed joint wheel; a first toothed joint wheel which is in matched connection with the second toothed joint wheels is rotatably at the middle portions of the second toothed joint wheels through a change-over shaft; the right end of the change-over shaft is rotatably installed in the right end wall of the second change-over slot, and the left end of the change-over shaft is connected with an electric rotation machine fixedly installed in the left end wall of the second change-over slot.