Definition: used to show a price, temperature, rate, speed, etc. Level: B2
当警察发现他时，他正以120英里每小时的速度行驶。
He was driving ___at 120 mph when the police spotted him.
每张票售价50美元。
The tickets are sold ___at $50 each.
房间温度保持在72华氏度。
The room temperature is kept ___at 72 degrees Fahrenheit.
