plug — an apparatus for splitting stone, consisting of two tapered bars (feathers) inserted into a hole drilled into the stone, between which a narrow wedge (plug) is hammered to spread them.
purpose — the reason for which something exists or is done, made, used, etc.
risk — exposure to the chance of injury or loss; a hazard or dangerous chance: It's not worth the risk.
scratch — to break, mar, or mark the surface of by rubbing, scraping, or tearing with something sharp or rough: to scratch one's hand on a nail.
seek — to go in search or quest of: to seek the truth.
strain — to draw tight or taut, especially to the utmost tension; stretch to the full: to strain a rope.
sweat — to perspire, especially freely or profusely.
drive at — to send, expel, or otherwise cause to move by force or compulsion: to drive away the flies; to drive back an attacking army; to drive a person to desperation.
go for — to move or proceed, especially to or from something: They're going by bus.
