铝及铝合金铰孔、攻丝，宜采用（）作切削液。
A.乳化液
B.苏打水
C.机械油
D.煤油
参考答案：D
On hearing the horrible noise, they all went out and looked at what was happening in________.[ ]
A. amusement
B. enjoyment
C. amazement
D. embarrassment
急性蜂窝织炎的主要致病菌是 ( )
A．金黄色葡萄球菌B．溶血性链球菌C．绿脓杆菌D．破伤风杆菌E．梭状芽孢杆菌
