Science uses observations of phenomena in order to make interpretations. Which of the following is an observation? a Pressure was applied slowly to fold the rock. b A fold is visible in an outcrop. c Heat was applied to soften the rock. d The fold was created by pressure.

explanation:

idk

a symbiotic relationship with the mitochondria

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.

"it built up in the atmosphere"

i think thats it, idk, i tried looking for this exact q& a for grad. and idk if i got this question right or sorry if im wrong