Relative explainations:
<subzero> <minus>
Examples:
1. 昨夜溫度是零下五度。
It was five below zero last night.
2. 更冷。氣溫將降至攝氏零下五度。
Colder still. The temperature will drop to five below zero.
3. 溫度突然下降到零下10度。
The mercury dived to ten below zero.
4. 溫度計指著零下十度。
The thermometer shows ten below zero.