tooth surface

基本解釋

Low power scanning electron microscope image of tooth surface, computer-coloured yellow on blue background.
牙齒表面的電子顯微鏡掃描圖。
Hold the floss tightly against the tooth, and move it away from the gum. Slide it firmly down the tooth surface, combining this with a back-and-forth motion.
牙線緊緊地貼著牙齒，往上向遠(yuǎn)離牙齦的方向移動，再沿著牙齒鄰面向下移動，把這個動作跟牙線的前后移動組合在一塊。
That means the toothbrush handle should fit comfortably in your hand and the toothbrush head should feel comfortable in your mouth and be able to reach every tooth surface.
那就是說，牙刷柄應(yīng)該合手，牙刷頭應(yīng)該合嘴并能刷到牙齒的每個面。