题目

At last we came to a town and found a quiet hotel, . A . next to it was a thick wood B . next to which was a thick wood C . next to it a thick wood was D . next to which a thick wood was 答案：B一列简谐横波沿直线传播，该直线上的a、b两点相距4．42m．图中实、虚两条曲线分别表示平衡位置在a、b两点处质点的振动曲线．从图示可知(    )A．此列波的频率一定是0．1 HzB．此列波的波长一定是0．1 mC．此列波的传播速度可能是34 m／sD．a点一定比b点距波源近