Question

Заполните пропуски: If I … a dinosaur skeleton one day, I … a world-known archeologist. found; will have become would find; became found; would become will find; become

Answer 1

Found, would become.
Посколько действие невозможное, то тут используется II Conditional:
( If + Past.Simple ) + ( would + V1 ( result part))

Answer 2

If I found a dinosaur skeleton one day, I would become a world-known archeologist.

Остальные варианты грамматически не верно построены, потому не подходят.

Answer 3

If I found a dinosaur skeleton one day, I would become a world-known archeologist.