A stock of animals or plants within a species having a distinctive appearance and typically having been developed by deliberate selection.

Movement to and fro or around something, especially that of fluid in a closed system.

A way in which something is usually done.

The process of evolution or being growth

a confrontation or unpleasant struggle.

Become or make larger or more extensive.

A group of people of similar age involved in a particular activity.

A flat or curved component, typically rectangular.

A number of events, objects, or people of a similar or related kind coming one after another.

opposite word

"employers should ... the needs of disabled people"

S+have/has+been+V+ing

I ... the house this summer.

The kids ... for two hours.

I ... (teach) this class for one hour.