per

柯林斯詞典

1. PREP You use per to express rates and ratios. For example, if something costs $50 per year, you must pay $50 each year for it. If a vehicle is travelling at 40 miles per hour, it travels 40 miles each hour. 每[amount PREP n]
...$6 per week for lunch. …每周$6喫午飯。
2. per head→see head

They cut 2p per litre off the price of unleaded petrol .
It costs a staggering $50,000 per week to keep the museum open to the public .
In China , the policy of one child per family was introduced to stabilize the country's population at 1.6 billion .
The train sped along at over 120 miles per hour .
The computer screen displays 80 characters per line .