实验室内进行猪链球菌菌种分离和保藏。
猪链球菌的危害等级为（）
A.无危害
B.Ⅰ级
C.Ⅱ级
D.Ⅲ级
E.Ⅳ级
参考答案：C
按烹饪原料的______分类，可将烹饪原料分为主配料、调味料和佐助料三大类。
A．加工与否
B．商品种类
C．烹饪运用
D．来源属性
—— We expected you yesterday.
—— I'm sorry, I______you to say that I couldn't be here until today.
A． should have called
B． must have called
C． could call
D． would call
