单选题 Until the twentieth century, pendulum clocks were calibrated against the rotation of earth by taking astronomically measurements.
【正确答案】 D
【答案解析】 答案:D:astronomical 分析:measurements是名词,修饰名词应该用形容词,astronomical天文学的adj. 参考译文:直到二十世纪,(意译)摆钟才通过天文方面的方法被校准,从而摆脱了地球自转的影响。