underground space; subterranean space; subterranea
front entrance; front door
to have one's attention attracted (caught); to be preoccupied with
to remind (someone of something); to call attention to; to make sure of; to emphasize; to emphasise
diving; diver; unlicensed (doctor, driver, etc.); unregistered; outsider; stranger
high alert; a state of high alert; on alert
your; indicates high rank or status; indicates love and respect (usu. for an older person)
just above; right overhead
blind spot (on the retina); blind spot; weak point; loophole
textbook; coursebook; schoolbook
consideration; inquiry; enquiry; investigation; study
the most one can do; the best one can do; the best one can expect
sounds good; sure thing; no problem
direct access; random access
law-like nature; regularity
carbine (short gun used by cavalry)
within expectations; as expected; within the scope of hypothesis or assumption
huge rock; firmness; solidity
fourth dimension; four dimensions
imagination; supposition; virtual; potential (enemy)
complexity; complex; complicated
to miss out on going; to fail to go
unperceived; unnoticed; unnoted; out-of-the-way; out of sight; inconspicuous
frequency (esp. of waveforms)
to listen attentively to; to be lost in
years gone by; earlier years; former years; the past
famous piece of music; excellent song; (musical) masterpiece
belligerence; fighting spirit
to stir up; to poke (the fire); to beat (an egg); to arouse (interest, feelings, etc.); to stir; to stoke