Questions

The receptor molecules, which receive signals from outside the cell, passing the signal to the inside.

In order for a nerve cell, or any cell, to perceive its environment, it needs a sensory apparatus. And for an individual cell, most of that sensation is derived at the cell surface. So, it expresses on its cell surface proteins that span across the membrane.

In the outside world, these proteins can act to receive signals, catching molecules on the outside and then as the molecule passes to the inside of the cell, they can send signals like alarm signals that can tell the cell that a particular molecule is outside.

Hence, here B is the receptor cell.

When a candidate is officially nominated at the national convention, then the presidential campaign begins.

Latitude comes first among latitude or longitude. 

Latitude is written before longitude. The first number is always the latitude and the second is the longitude.

Latitude is written with a number, followed by either “north” or “south” depending on whether it is located north or south of the equator. Longitude is written with a number, followed by either “east” or “west” depending on whether it is located east or west of the Prime Meridian.

TIME is what we can measure in Years, Months, Days, Hours, Minutes and Seconds but we cannot see.