difficult to ...; hard to ...
clear writing; specification
infection; contagion; becoming infected
necessary; needed; essential; necessity; need; requirement
may; might; perhaps; may be; possibly
environment; circumstance
betterment; improvement; kaizen (Japanese business philosophy of continuous improvement)
or; either ... or; maybe; perhaps; some ... and others ...; sometimes ... and at other times ...
to harm; to hurt; to injure; to fail to ...; to miss one's opportunity to ...
medical care; medical treatment
actual spot; scene (of a crime, accident, etc.); (on) site; (on) the ground; filming location; (movie) set
recommendation; endorsement
way; method; means; resource; course
to amass; to accumulate; to store; to leave unpaid
or rather (say); or better (say); or perhaps I should say; or, how should I put it,...; I mean
abruptly; suddenly; all of a sudden; without warning
with a clatter; with a rattle; empty; bare; raspy (voice); gravelly; with a gargle
good; advantage; sake; purpose; consequence; result
bulging; swelling (e.g. with water); loose-fitting or baggy (clothing); bubbling; foaming
time; hour; period; class
second (unit of time); arc second
purpose; goal; aim; objective; intention
inner part; inside; interior; depths (e.g. of a forest); back (of a house, drawer, etc.); bottom (e.g. of one's heart)
reverse; opposite; converse (of a hypothesis, etc.); inverse (function)
to carry; to transport; to come; to go; to wield (a tool, etc.); to use
riskiness; (level of) danger
(just) making sure; just to be sure; just in case; for caution's sake
to repeat; to do something over again
one more time; once more; once again
to scrape out; to rake out (e.g. ashes); to bail out (e.g. water)
body; torso; trunk; build; physique; health
outside; exterior; the open (air); other place; somewhere else
image (in one's mind); impression; (computer) image; depiction (e.g. of a product); rendition
ah!; oh!; yes; indeed; aah; gah
to speak; to say; to vocalize
oh!; good heavens!; ugh!; oh no!; ah!; the penny drops!
easy; likely to ...; have a tendency to ...; easy to ...
different suitabilities; being cut out for certain things (and not for others)
interest (in something); curiosity (about something); zest (for)