英语专八考前自测冲刺改错题1_TEM8试题

    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.