单语范例（未经PONS编辑处理）
With such a material, the perpetual motion device would be possible.
en.wikipedia.org In order for this perpetual motion to work, the system must not radiate its rotational energy.
en.wikipedia.org Few defenders had remained, and these, worn out by their perpetual fighting and vigilance, usually slept during the last watch of the night.
en.wikipedia.org Perpetual penalties can not be imposed or declared by decree...
en.wikipedia.org Finally, she will petition to make her perpetual profession, taking permanent, solemn vows.
en.wikipedia.org