英和和英

a duplicate copy

a duplicate copy

copy on a duplicator

make a duplicate or duplicates of

a duplicate copy as a reserve

triplicate copies

original and duplicate

original and copy―duplicate copies

original and copy―duplicate copies

a duplicate copy of a securities note

a duplicate copy of an original document

an exemplified copy

make multiple identical copies of

a duplicate copy of a contract

the act of copying or making a duplicate (or duplicates) of something

counterexample

repeated copying leads to a multiplication of errors

to measure cloth

Similar poles repel each other.

Converse

diametrically opposite

to rebel against an authority

by common consent

in inverse proportion [relation] to…

to reciprocate

polar opposites

a foul blow

make a countercharge

reciprocal action and reaction

contradict