英语专八考前自测冲刺题：改错上
|
本文是英语专业八级考试中的改错题型，供考生在考试前做自我测试之用。 We’ve all used thermometers to measure temperature but sometimes we need to measure temperature in places you （1） __ can’ t put a thermometer —— for example， inside a rocket engine. One of the best methods for those really hard-to-get-to place is based on laser spectroscopy. Light from a laser point- （2） __ ing at the region of interest is absorbed by molecules and some （3） __ of it are re-emitted back towards the source where it can be （4） __ measured. The re-emitted fight is shifted in frequency （changed in wavelength） by amounts that depend on the molecule and also the temperature and pressure of the surrounding gas be- （5） __ cause of collisions among the molecules. The single， sharp frequency from the laser is thus smeared out into a whole spectrum of frequency whose shape can be used to determine （6） __ the temperature provided so that the molecular transitions and （7） __ line shapes are known. Because it is the main component of the air， it is convenient to use nitrogen since its molecular （8） __ properties are known from room temperature to temperature of about 1，200 degree Celsius from experimental measurements. （9） Although this is a large range， it is far short of what it is needed （10） __ for， some applications. 相关资料 |
