Unit 4

STUDY
PLAY
accumulate
to gradually get more and more of something over a period of time (v)
adequate
enough or sufficient (adj)
author
a writer (n)
debate
an argument or discussion expressing different opinions (n)
depress
to make sad or gloomy (v)
indicate
to show that something is true or exists (v)
invest
to spend money on something in order to make it better or more successful (v)
persist
to continue to do something despite difficulties or opposition (v)
precede
to happen before something (v)
protocol
a system of fixed rules and formal behavior (n)
reluctant
unwilling to do something (adj)
sustain
to keep something going, such as an action or process (v)
text
the main printed part of a book (n)
volume
the amount of something (n)