proxy; agent; substitute; deputy; alternate; representative
objection; refutation; rebuttal; counterargument
document; letter; writing; contents (e.g. of a letter)
to become serious; to take something seriously (joke, teasing); to become irritated or angry (usu. at something trivial); to get worked up
pursuit of knowledge; studying; learning; training; completing a course
to be sufficient; to be enough; to be worth doing; to be worthy of; to do (the job); to serve
relatedness; associativity; relation; relationship; relevance
firm; determined; resolute; conclusive