Englishfor English speakers
concentration
Noun
—
A concentration is a large amount of something in one place or group.
The oil-sands in Alberta, Canada, contain high concentrations of oil.
The growing concentration of people in cities is causing new problems.
—
Concentration is the ability to focus your attention on something.
Runners mustn't worry or do anything else to break their concentration.
A clean desk in a quiet place will help students improve concentration.
The government's concentration should be on helping those in the greatest need.
—
The amount of solute in a solution; the concentration of a solution is measured in parts per million (ppm)
wave
Noun
—
A wave is the motion of water up and down.
wave
Verb
—
To move from side to side again and again.
The flag waved in the wind.