Loading question...
« Prev Next »
You are in free guest mode. Timed Practice Revision List Attempt History Progress Tracking Create a free account to unlock these tools
Practice Speaking: Read Aloud ID: #51813 Long Underground Microbes
Instructions
Precambrian cratons some of Earth's oldest rocks were uninhabitable for microbes for much of their existence, with the longest period of habitability not much beyond a billion years, and many only for the past 50 million to 300 million years, according to a paper correlating Earth's deep biosphere with geologic history.

Accuracy Comparison for Reading Scores

Accuracy:

Sample Answers:

Status: A.I. Engine Standing by...
Comments: