以下哪些是两性电解质?
A. 氨基酸
B. 蛋白质
C. 磷脂酰胆碱
D. 粘多糖
E. 葡糖醛酸
板后浇带的代号用()表示。
A. HJD
B. SJB
C. FB
D. BD
板翻边可为上翻和下翻,实线表示()。
A. 上翻边
B. 下翻边
C. 左翻边
D. 右翻边
Food for cows requires a lot of____.Cows produce a lot of ______, including methane.Wheat for buns requires a lot of ____.Meat has to be kept ____.You have to ____ meat from place to place.