经过加工处理的直接入口食品中带有病原菌,可能是受到()污染所致。
A.泥土、灰尘
B.生的食物
C.受到污染的操作环境
D.废弃物
参考答案:A, B, C, D
It is deemed as impolite to leave a party without saying "good-bye" to the host.
A. insisted B. condemned C. convinced D. considered