Sentence:  In the relatively <WSD>short</WSD> time since these early observations , Venus has been observed at additional wave lengths in the range from 0.8 to 10.2 cm , and Jupiter has been observed over the wave-length range from 3.03 to 68 cm . 
Meaning of the word marked with <WSD> tags:  primarily temporal sense; indicating or being or seeming to be limited in duration