an ‘exotic’ species is a species that has been introduced by humans to regions outside its historic range.

sometimes we make matters worse by introducing exotics to control previously introduced exotics.

the rosy wolfsnail was originally introduced to hawaii in the 1950s as a biological control agent to reduce populations of another exotic snail, the giant african snail.

the rosy wolfsnail is unfortunately a more generalist predator than had been expected; it eats far more species than giant african snails.

it has an unfortunate preference for native hawaiian snails and more than 15 native snail species have been driven extinct. so far, the only means of reducing damage by the rosy wolfsnail has been the construction of special fences, lined with salt barriers, to keep the snail out of the habitat of the native snail species.

특히 두번째 빨간 줄을 잘 모르겠어요. 예를 들어 this is better than i expected. 라고 하면 지금 보는 건 이거지만 이미 기대했던 건 그전이니까 그 앞선 시간을 나타내기위해 과거동사를 쓴건 알겠는데......

두번째 빨간줄엔 is....인데....had been expected.......현재, 과거, 대과거 인데 어떻게 시간을 현재에서 대과거로 뛰어넘을 수 있는거죠? 모의고사 문제니까 틀릴 리도 없고.

....is.... has been expected나 was expected라고 해야하는 게 아닌지요?

an ‘exotic’ species is a species that has been introduced by humans to regions outside its historic range. 그리고 이부분은 인간에 의해 도입된게 얼마 안된 지금까지도 연결이 되어있어서 현재도 영향을 받으니까 is 인데오 현재완료수동으로 쓴건가요? 이걸.....is.....was introduced라고 하면 어떤 의미가 되는건가요?
어느 과거에 인간에 의해 유입된 종....이란 의미외에 지금도 영향받는진 모르니까 현재완료 수동으로 쓴건가요?

근데.....사실....the rosy wolfsnail is unfortunately a more generalist predator than had been expected; it eats far more species than giant african snails. 이부분이 정말 이해가 안가네요.

의미로도 문법으로도.......에고........특히 의미부분으로 왜 이게 나오고 was expected랑 has been expected가 되면 그땐 어떤 뜻이, 어떤 의미가 되는지......설명해주실수 있는 분이 계시면 정말 감사하겠습니다. ^^~ 넘 궁금해서요.....