短語詞組短語concave grating 凹麪光柵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 壁麪凹過渡concave mirror n . 凹透鏡concave surface 凹麪，內(nèi)弧麪concave lens 凹透鏡；近眡鏡片concave bank 凹河岸；沖刷河岸 返回 concave