Which set of traits best characterizes the amphibian class?

select one:

a. tetrapod, gills, moist skin, scales

b. tetrapod, lungs, moist skin, scales

c. tetrapod, gills, lungs, scales

d. tetrapod, gills, lungs, moist skin

The bacteria found in soil is usually harmful and measures are taken to remove any traces of microorganisms. true or false

Crinoids, also known as sea lilies, appear to be sea plants but are not plants at all. crinoids are an echinoderm species which uses anchoring structures called holdfasts to attach themselves to the sea floor. crinoids were most abundant in pennsylvania during the mississippian period, which ranged from 375 to 320 million years ago. fossils of the crinoids shows that during most of this time pennsylvania was that provided favorable conditions for crinoid growth. a) glacial terrain b) a dry and sandy plain c) mostly mountain ranges d) covered by warm, shallow seas

The changes that the students observed, rapid breathing and sweating, would be classified as a to a change in a system.