題目：
Scientists are thrilled about some tiny, furry finds. They have discovered two
new species of lemurs on Madagascar, an island _______ off the southeast coas
t of Africa.
① locating
② to locate
③ located
④ been located
答案：③
疑問：為何選③？這是屬於何種用法？

(which is/was) located off of 座落於XX之外

了解了，謝謝！