How are babies in the womb for 9months but aren't 9months when they are born

Strictly social convention.
Some ancient cultural traditions ... China, for example,
give a baby credit for 1 year when it's born.

Jet streams are relatively narrow bands of strong wind in the upper levels of the atmosphere. the winds blow from west to east in jet streams but the flow often shifts to the north and south. jet streams follow the boundaries between hot and cold air. the earth's rotation is responsible for the jet stream as well.

Where is the table ? you can take a picture of it