Bats can produce and hear infrasonic sound.
Complete the following sentences :
(a) An average person can hear sound of frequencies in the range ___ to ___.
(b) Ultrasound is of frequency ___ .
(c) Infrasonic sound is of frequency ___ .
(d) Bats can produce and hear ___ sound.
(e) Elephants produce ___ sound.
To detect the obstacles in their path, bats produce :
(a) infrasonic waves (b) ultrasonic waves
(c) electromagnetic waves (d) radio waves.