1. Proficient= able to do something well or skillfully
proficient in/ at
E.g. Martha’s proficient in Swedish.
E.g. There’s only one way to become proficient at anything – practice!
E.g. To do a multimedia presentation you need to be proficient in public speaking.
—proficiently adv
2. exponential= increasing or growing very fast
e.g. exponential growth
e.g. exponentially
3. exacerbate= to make a problem worse
4. unprecedented= never having happened or existed before
e.g. The government took the unprecedented step of releasing confidential correspondence.