短語詞組短語concave grating 凹面光柵concave slide [光]凹玻片;凹槽載片concave refractor 上凹折射層concave domain 凹型區(qū)域concave share 凹形犁鏵concave frame 凹板骨架geosynclinal concave 地槽凹concave cam [機]凹形凸輪concave transition 壁面凹過渡concave mirror n . 凹透鏡concave surface 凹面,內(nèi)弧面concave lens 凹透鏡;近視鏡片concave bank 凹河岸;沖刷河岸 返回 concave