n.跷跷板，上下动；adj.前后动的，交互的；vt.使上下（来回）摇动；vi.玩跷跷板，上下（来回）摇动； 变形： 复数：seesaws过去式：seesawed过去分词：seesawed现在分词：seesawing第三人称单数：seesaws 英英释义： seesaw[ 'si:sɔ: ]n.a plaything consisting of a board balanced on a fulcrum; the board is ridden up and down by children at eith