因用途不同，订购单可分为多联，其中由供应商签字确认后寄回给企业的称为（）。
A.厂商联
B.物料联
C.承办联
D.回执联
参考答案：D
— Dad, there's something wrong with my watch.
— ______. I can mend it for you. [ ]
A. You're right
B. That's right.
C. Never mind
D. That's OK
人耳感受性和耐受性都比较高的声音频率范围是（）。
A.100～1000Hz
B.1000～4000Hz
C.5000～10000Hz
D.10000～15000Hz
