对于某个旅游企业来说，那些经常重复购买但同时对企业抱有消极态度的顾客是（）的顾客。
A.真正忠诚
B.潜在忠诚
C.虚假忠诚
D.不忠诚
参考答案：C
You can never know ________ when she received our nice birthday presents.
A．how Mary was excited
B．how excited Mary was.
C．How excited was Mary
D．Mary was how excited
副溶血性弧菌所致疾病是（）
A.霍乱
B.食物中毒
C.肺炎
D.败血症
E.肠热症
