Consumers view genetically-engineered foods as "not natural", having "unknown consequences", "harmful",
"controlled by others", and "risky", all well known outrage factors.
http://www.bartleby.com/64/C003/0221.html
The noun pair can be followed by a singular or plural verb. The singular is always used when pair refers to a set considered as a single entity: This pair of shoes is on sale.
A plural verb is used when the members are considered as individuals: The pair are working more harmoniously now.
After a number other than one, pair itself can be either singular or plural, but the plural is now more common: She bought six pairs (or pair) of stockings.
(I think) This is correct:
Each pair in A and B, C and D, and E and F contain a shared component.
This seems less clear to me:
Each pair of A and B, C and D, and E and F contain a shared component.
(but maybe this is closer to normal (non-Geeky) English.)
This also seems less clear to me:
The pairs A and B, C and D, and E and F respectively contain common components.
