The first supercontinent present by Proterozoic time was Vaalbara
a. True
b. False
True
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At which of the following altitudes is the base of an altostratus or altocumulus cloud generally found at middle latitudes?
A. between 60 and 2,000 m B. between 2,000 and 7,000 m C. between 7,000 and 13,000 m D. above 13,000 m
Based on soil particle size, the largest to smallest soil types are
A) sand, silt, and clay. B) sand, clay, and silt. C) clay, sand, and silt. D) silt, sand, and clay.
The most common gas in the atmosphere is
A. methane (CH4). B. oxygen (O2). C. carbon dioxide (CO2). D. nitrogen (N2).
Criteria pollutants are those that
A. Are easiest to get rid of B. Contribute the most to air quality degradation C. Cause the most damage to buildings D. Are most highly toxic even in small quantities E. Set the standards for other pollutants