单项选择题

稳态噪声是在观察时间内，采用声级计“慢”档动态特性测量时，声级波动小于（）的噪声。
A、1dB
B、2dB
C、3dB
D、4dB

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The two major political parties are (1) which is thought to be more liberal; and the Republican Party which is believed to be more conservative.

答案：填空(1)： The Democratic Party 。

单项选择题