Author Question: Microscopic crystals of silica form a hard rock called chert, which can be shaped to form sharp ... (Read 157 times)

j.rubin · **on:** Jul 13, 2018

Microscopic crystals of silica form a hard rock called chert, which can be shaped to form sharp cutting edges.
Indicate whether the statement is true or false

Question 2

Fossil evidence suggests that such land-dwelling arthropods as _____ had evolved by at least the Devonian.
A)trilobites
B)molluscs
C)scorpions
D)beetles
E)spiders