单词	sad day
释义	sad day 悲痛的日子
随便看	primary org unit indicato primary orientation primary orientation flat primary orifice primary original evidence primary orogeny primary orthostatic hypotension primary oscillation primary oscillator primary ossification center primary ossification point primary osteon primary osteoperosis primary osteoporosis primary otalgia Primary Other Aircraft Inventory primary outcome primary outcrop primary outlet primary outlet nozzle primary output primary oval foramen primary ovarian adenocarcinoma primary ovarian cancer Primary ovarian carcinoma