Find something that makes a very quiet, steady sound. A small fan on a low setting or a real, non-electric, ticking watch or clock are ideal.
找一些安静、稳定的东西，一台低音的小风扇，一只电子手表或钟是一个很好的选择。
Find something that makes a very quiet, steady sound. A small fan on a low setting or a real, non-electric, ticking watch or clock are ideal.
找一些安静、稳定的东西，一台低音的小风扇，一只电子手表或钟是一个很好的选择。
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