Did reptiles or amphibians occur first?

These factors threaten north americas ecosystems

The net below can be folded to form a square pyramid.la2419"100what is the surface area of the pyramid? 190.8 square inches| 0 217.8 square inches300. 6 square inches354.6 square inches

Ahis which describe the horizons in a soil profile? check all that apply. horizon a is mineral deficient. bedrock lies below the soil layers. te horizon o forms from organic material, horizon b undergoes the least amount of change. horizon c is least affected by the soil formation process.