A.發(fā)散入射同心光束的頂點(diǎn) B.會(huì)聚入射同心光束的頂點(diǎn) C.發(fā)散出射同心光束的頂點(diǎn) D.會(huì)聚出射同心光束的頂點(diǎn)
A.60° B.90° C.120° D.150°