adj.凹的
n.凹面；凹线；凹形
The palm of one's hand is slightly concave. 人的手掌是微凹的。
A cylinder is a hollow tube with a closed concave base that permits it to stand upright. 钢瓶是中空的管道，封闭的底部是凹入的，这样可以直立起来。
His figure looks very funny in the concave mirror. 他的样子在凹镜里显得非常可笑。
用作名词 (n.)These are aberration-corrected holographic concave gratings. 下表所列为像差校正全息凹面光栅。
The cloven hooves are sharp edged, elastic and concave. 蹄锋利，呈凹形，富有弹性。
adj.平凹的
adj.两面凹的
