NewHopeR
Senior Member
- Joined
- Nov 6, 2009
- Member Type
- Student or Learner
- Native Language
- Chinese
- Home Country
- China
- Current Location
- China
1) The second half of the twentieth century witnessed a watershed of progress in the medical sciences.
2) The second half of the twentieth century was a watershed of progress in the medical sciences.
2) The second half of the twentieth century was a watershed of progress in the medical sciences.