Using light as an external power source can alleviate the weight and mass of having an onboard system, leaving room for scientific payloads, for example, and it provides more propulsive power.

利用光束作为外部能量源可以减轻火箭自身携带的系统重量和质量，为科学研究扩大有效载荷空间，并提供更大的推力。

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Sculptures must, for example, be stable, which requires an understanding of the properties of mass, weight distribution, and stress.

例如，雕塑必须是稳定的，这就需要理解质量、重量分布和压力的特性。

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However, their focus was not on aerobics, but rather on weight-training programs designed to develop muscular mass, strength, and endurance in their primarily male enthusiasts.

然而，他们的重点并不是有氧运动，而是负重训练项目，旨在培养主要客户男性健身爱好者的培养肌肉质量、力量和耐力等。

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While there is advice aplenty on how to lose pounds or kilograms, a new study focuses on middle aged and older women who maintain normal body weight, or BMI (Body Mass Index) and do not diet.

VOA: standard.2010.03.30

Weight and mass are not equivalent as weight can change with gravitational changes.

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They measured height, weight and body mass index - calculated by dividing weight in kilograms by the square of your height in metres.

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The loss in weight and body mass is driven by a metabolic disease manifested by increased energy consumption.

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