Solution:

Submarine

Solution:

When the going gets tough, the tough get going.

Solution:

Rendezvous

Solution:

Arc + tick + circle.
= Artic Circle

Solution:

Yes it is possible only under the following condition or situation.

When the twins were born, their mother was on a ship or boat. The elder one was born on 1st of March. But just after his birth before the younger one could be born, the boat crossed the international time zone and thus, the younger one was born on 28th of February.

Now whenever, a leap year falls, the younger brother will celebrate his birthday two days before the elder one.

Solution:

It is called harmony. The reason is simple. The husband receives peace after giving that money to his wife.

Solution:

A man, who crawls on all fours as a baby, walks on two legs as an adult, and walks with a cane in old age.

Of course morning, noon, and night are metaphors for the times in a man's (person's) life. Such metaphors are common in riddles. There were two Thebes, apparently this Thebes was the one in Greece. And this Sphinx was apparently not the one at Giza, in Egypt.

Solution:

Double Letters

Solution:

JASON

July(J)
August(A)
September(S)
October(O)
November(N)

Solution:

The peahen lays eggs