teeter v.摇晃,蹒跚;犹豫不决;n.踉跄,摇摆; 跷跷板;
All eyes in the room are nervously fixed on the mine as it teeters on the brink.
房间里的所有目光都紧张地盯着矿井,因为处在危险的边缘。
retain vt.保持; 留在心中,记住; 雇用; 付定金保留
Daily facial exercises help her to retain the skin's elasticity.
每天做面部运动帮助她保持皮肤弹性。