参考答案和解析
正确答案：
C
解析：
从录音中提到的“The new technology works by “sniffing” the amount of oxygen in a car’s exhaust”，可知这项新技术通过感知汽车废气中氧的含量来进行调整。
【录音原文】
Petrol burns best with an air-to-fuel ratio of around 14:1. This means that, for every kilogram of fuel burnt, all of the oxygen in 14 kilograms of air will be consumed. Ethanol, though, requires an air-to-fuel ratio of 9:1. The new technology works by “sniffing” the amount of oxygen in a car’s exhaust. If too much or too little of the gas is sensed, it indicates that the fuel is burning in a less-than-optimal way, and thus that the air-to-fuel ratio is wrong. A signal is then sent to the engine to tweak the ratio appropriately.
