bacterium是可数名词; bacterium n. 细菌;bacteria的单数; 复数 bacteria Culture and Analysis of Content Bacterium in Sewage Liquid in Different Sea...
1 anthology n. 诗集,文选; 2 anthropology n. 人类学; 3 apology n.道歉,认错,谢罪; 4 archaeology n. 考古学; 5 astrology n. 占星学,占星术; 6 ...