Which animals possess a radar system to locate objects in the dark?

Members of which of the following groups have three ossicles in their middle ear?

Which of the following is an oviparous mammal?

$A$: The duck-billed platypus and the spiny ant-eater,both are egg-laying animals yet are grouped under mammals.
$R$: Both of them have seven cervical vertebrae and mammary glands without teats.

Which of the following mammals have a cloaca?

The Haversian canal is found in the bone of: