【简答题】公元11世纪,周武王曾建“灵囿”。____
【单选题】下列哪些不是外毒素的特点? 1主要由G-菌产生; 2毒性强;有特异性; 3刺激机体产生的抗毒素, 4毒性弱;无特异性,引起机体发热; 5能制成类毒素,有免疫预防功能
【单选题】Their products enjoy 30 percent_____ of the market in this country because both the quality and their service are fine.
【单选题】Their products enjoy 30 percent ________ of the market in this country because both the quality and their service are fine. [ ]
【单选题】Their products enjoy 30 percent _____ of the market in this country because both the quality and their service are fine. [ ]