Question

as marine researcher william watkins listened to the sounds of the sea, he noticed something strange: a whale call at 52 hertz. it was a very unusual pitch, or frequency, much higher than that of any known baleen whale. blue whales, humpbacks, and other baleen whales have deep, low - frequency songs, ranging between 10 and 40 hertz. toothed whales, like orcas, often sing at higher pitches. but everything else about the sound was unmistakably baleen. this whale seemed to have somehow strayed from the others.
frequencies between 10 and 40 hertz are particularly good for sending sound waves through water. low - frequency sounds lose less energy as they travel and can cross entire oceans. thats how blue whales chat across hundreds of kilometers. sounds at a higher frequency, like 52 hertz, cant travel as far—and may not even be audible to other whales.
still, the strange, higher - pitched calls kept coming, year after year. watkins and his team tracked this whales call across the northern pacific ocean for more than a decade. though the whale seemed to follow seasonal migration patterns similar to other large whales, no other animal ever responded to its song. it appeared to be completely alone.
scientists have a few different ideas about this hypothetical whale. it could have a physical difference. perhaps this whale is a hybrid species. or, it could even be an undiscovered species, though that possibility is unlikely. why this whale—if it is a whale—sings at 52 hertz remains unknown.
watkins passed away in 2004, having never seen the whale whose voice he came to know so well. as of 2023, that same song continues to echo through the deep. the 52 - hertz whale is still known only by its voice. it remains one of the many mysteries of the deep ocean.
question 1 of 6
1 fill in the blanks to complete the sentences
william watkins discovered a whale call with an unusual
the calls pitch was
than that of other baleen whales.

Explanation:

The first blank is filled with "frequency" as the text mentions "it was a very unusual pitch, or frequency". The second blank is filled with "higher" as the text states "much higher than that of any known baleen whale".

Answer:

frequency; higher