In grammar, tense is a category that expresses time reference.[2][3] Tenses are usually manifested by the use of specific forms of verbs, particularly in their conjugation patterns.
In grammar, tense is a category that expresses time reference.[2][3] Tenses are usually manifested by the use of specific forms of verbs, particularly in their conjugation patterns.
Coral reefs are a highly productive marine ecosystem.[2]
There are many different ecosystems on Earth. Left: Coral reefs are a highly productive marine ecosystem[1], right: Temperate rainforest on the Olympic Peninsula in Washington state.
An ecosystem is a community made up of living organisms and nonliving components such as air, water, and mineral soil
Coral reefs are a highly productive marine ecosystem.[2]
There are many different ecosystems on Earth. Left: Coral reefs are a highly productive marine ecosystem[1], right: Temperate rainforest on the Olympic Peninsula in Washington state.
An ecosystem is a community made up of living organisms and nonliving components such as air, water, and mineral soil
