The necessary conditions of imbed a Disapearing of the pellucid zone a Syntrophoblast formed from the blast a Synchronizing development of blast and the endometrium 口 P Secretory enoughThe necessary conditions of imbed ❑ Disapearing of the pellucid zone ❑ Syntrophoblast formed from the blast ❑ Synchronizing development of blast and the endometriun ❑ P Secretory enough