During which era did mosses, ferns, and conifers first appear? 8.
e.6a.1 * cenozoic mesozoic paleozoic

Which of these statements best explains why space exploration should be encouraged? it prepares humans to live without oxygen. it dispel myths about objects in space. it prevents comets and asteroids from striking earth. it creates technology to absorb harmful radiations in space.

A0.100-kilogram apple hangs in a tree 1.50 meter above the ground. ignore frictional effects, the total mechanical energy of the apples is

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost