1. Although Britain and France both use the metric system and the same electrical voltage (220 volts), it sometimes seems as if they have little else in common.
    尽管英法两国都使用公制和相同的电压（220伏），有时候看上去倒是少有类同。

2. Portable boiling elements that can boil small quantities of water are useful when the right voltage of electricity is available.
    如果有相配的电压，可以煮少量水的便携式热水装置是有用的。