英和和英

a duplicated thing

an exact duplicate

raise to the second power

to reprint

is/are duplicated

undergo polymerization

to publish a work in a series

（賃銀なら）to charge an extra―（配当なら）―give a bonus

add up to

to reciprocate

a condition in which an action is very difficult to carry out

to put two sheets together―put one sheet on another―put one sheet on top of another

to double-track a line―duplicate a line

rearrange

to pair―twin

to bind a book in paper

to win successive victories

overlap

to double

fix to

to be consistent

do multiplication

to copulate

have a double

to interpose

to combine two classes―（団体なら）―unite two parties

to agree on other's opinion, not having one's own

to neglect a matter―slight a matter―let things slide

to coincide

twofold