Until now, they explained, an external source of electricity was required in order to power the process.

但是目前还需要提供外部电源来启动这个过程。

youdao

Experts fear that Britain is relying too much on wind as a power source when other technologies are required in calm weather.

有专家担心，其他技术要求大气平稳时，英国却过度依赖风力作为其能源。

youdao

Having initially connected the ornithopter using a DC power source, they realized that the device could lift 1.5 grams of payload, which was roughly the mass of the batteries required for flight.

起初给扑翼机接上一个直流电源之后，他们发现这个装置的有效载荷为1.5 g，这大概可以勉强提起飞行所需的电池。

youdao

Admittedly, this unusual memory requires an internal light source, but the amount of illumination required is tiny and consumes less power than the logic circuits that are used to read data in and out.

ECONOMIST: Just press print