Prime meridian divides the earth into western and eastern hemispheres
A meter or metre is the base unit of length in the International System of Units. It’s basically a measurement/unit
I believe the answer is D. The NASA mission which sent a probe to collide with a comet's nucleus is the Deep Impact. It is the first mission sent in order to see the interior of a comet. The comet that was aimed was called the Comet Tempel 1.
