a completely new stage的用法和样例：
- The human race has entered a completely new stage in its history.We havecrossed the threshold of the 21st centurythe curtain of the new millenium is slowly rising.
- A completely new airliner was produced.
- They've given the place a completely new look.
- And ushered in a completely new age.
- She conjectured the existence of a completely new species.