ex‧ten‧sive W3 / ɪkstensɪv / 形容词

1 large in size, amount, or degree :

The house stands in extensive grounds.

Fire has caused extensive damage to the island’s forests.

the extensive use of pesticides

2 containing or dealing with a lot of information and details :

Extensive research is being done into the connection between the disease and poor living conditions.

The exhibition has received extensive coverage in the national press.

— extensively 副词 :

As a student, he travelled extensively in the Middle East.