In order for the apple trec experiment to be valid scientifically, both orchards must: * receive the same amount of sunlight
receive the same amount of water
have the same species of apple tree
all of these
What do you call the variables that are maintained or kept the same throughout an

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.