This article discusses the discovery by scientists from the U.S. and Australia of the remains of a huge meteorite hole on the northwest coast of Australia; which, researchers think, caused the mass extinction of life on earth two hundred fifty million years ago. The following study by a scientist from University of California at Santa Barbara supported this theory. However, some other scientists issued different opinions.
- Chinese, Mandarin (Traditional)
- Superior, Advanced-High
- This ACTFL rating is an approximation based on the ILR level
- Maintenance & Improvement
- Learning Object