"It describes the power needed to propel a bike against our everyday foes: gravity, weight, friction, wind resistance," he writes.

“它描述了推动自行车克服日常阻力——如引力、重量、摩擦力以及风阻——所需要的能量，”他这样写到。

A keel also provides weight low under the water to lower the boat's center of gravity below the waterline, which is needed so that the boat bobs back upright if knocked over by wind or waves.

龙骨同时也增加了船只的底部重量，从而将船只重心降到吃水线之下，而这对于船只在被风浪打翻时能够得以及时回正是十分必要的。

Upstanding toothbrush makes use of a weight at the end of its rounded handle to create a centre of gravity at the handle base.

可站立式牙刷利用自身圆胖的手柄底端的重量来让重心点落在手柄底部。

Lift yourself off the floor by carefully shifting your center of gravity. Press your hands into the floor and slowly begin to rock your weight back, off your feet and onto your hands.

双手扎实地按向地面，慢慢将重量向后放，重心落在双手上，抬起双脚。

Your center of gravity has shifted and all that extra weight around your middle may be pulling your back out of whack and messing with your balance.

你的重心已经发生偏移了，所有环绕在你腰腹部的增加的重量可能会使背部不一致并干扰你的平衡力。