日期:
来源:雅诚德英语网
It was only when electric motors became advanced that vacuum cleaners became common.
只有电动机变得先进时,真空吸尘器才会普遍使用。
It was only when electric motors became advanced that vacuum cleaners became common.
只有电动机变得先进时,真空吸尘器才会普遍使用。