What do lots of tourists go to Rome for？（）
A. Different.
B. Shining sun.
C. Good life.
D. Food.
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What’s the relationship between the two persons？（）
A. Wife and husband.
B. Salesman and customer.
C. Teacher and student.
D. Employer and employee.
采样频率与量化单位有关。( )
A. 对
B. 错
假定标准声压po=0.0002μbar，在距离声源2m处，测得的声压为2μbar，问其相应的声压级是多少
视频系统的传输方式对图像质量并无影响。( )
A. 对
B. 错
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