The ear ossicles in the middle ear, from outside to inside, are:

The Eustachian tube connects $A$ cavity with $B$. Choose the correct option for $A$ and $B$.

The fluid that fills the membranous labyrinth of the rabbit is called .....

$P$ is a continuous tubular structure. Inside these tubes, $Q$ is arranged.
$\quad\quad\quad P \quad\quad\quad Q$
$(A)$ $Scala \text{ vestibuli} \quad$ $Scala \text{ media}$
$(B)$ $Scala \text{ media} \quad$ $Scala \text{ tympani}$
$(C)$ $Scala \text{ tympani} \quad$ $Scala \text{ media}$
$(D)$ $Scala \text{ media} \quad$ $Scala \text{ vestibuli}$

The labyrinth,a fluid-filled inner ear,consists of:

Our ear can hear the frequency of sound waves in the range of: