100000000000
0 pairs
up to four pairs is the answer
12 has 3 factor pairs and the pairs are (1,12), (2,6) and (3,4).
It has 6 possible pairs of sides, although all the pairs will look the same. It has 6 possible pairs of angles, although all the pairs will look the same.
There are infinitely many pairs. For example 23.5 and 75.5 or -3 and 102.
South Indian Earthworm is the common name of megascolex. Its scientific name is Pheritima Posthuma.
According to my Snapple cap, The common garden worm has 5 pairs of hearts
Earth worms have 4 pairs of heart. pheretima has 4 pairs of hearts.
An earthworm, Annelida [= ringed] has up to five pairs of hearts.
by the help of the heart
Many, many pairs.
They are pairs of chambers inside the heart, which have valves.
It has 2 pairs.
3 pairs
Six pairs
Two pairs.
23 pairs