词汇	umbilicusor navel
释义	umbilicusor navel 脐
随便看	period of expansion period of extension period of fermentation period of fetus period official period of filter service period of first impounding period of flaming Period of flower period of folding period of forecast period of formal operations period of free oscillation period of freezing weather Period of fruit-setting Period of German Occupation period of gestation period of governing Hubei period of grace period of growth period of guarantee period of gymnosperms period of half chang period of half change period of half decay