第13题: [单项选择]信号噪声比是指() A. 信号强度与噪声的差值 B. 信号强度与噪声强度的比值 C. 信号强度与噪声强度的比值乘以固定的系数 D. 信号强度与噪声的和 E. 信号强度与噪声的积 参考答案:B 答案解析:信号噪声比是指信号强度与噪声强度的比值,提高信号强度和降低噪声强度可以提高信噪比。
第27题: [单项选择]What will the woman probably do A. In a restaurant. B. In a hairdresser’s. C. In a car. D. In a swimming pool. 参考答案:C 答案解析:[听力原文] W: It’s about one o’clock and I’m starving. There still seems a long way to go. M: Why