Answer:
The correct answer is option (D) there was a time in Pennsylvania history when dinosaur existed.
Explanation: A paleontologist discovers a rock slab on which the footprints of a Pennsylvania dinosaur are well preserved. This means that there was a time in Pennsylvania history when dinosaur existed in this area. Here fossil is a fragment of rock on which the footprints of dinosaur is present.
The answer would be:
B. Sequence of the bases in DNA molecules.
Here is more about your questions:
DNA contain the instructions of the traits of an organism. Most of the organism have the same DNA but what makes each different is the sequence of the DNA. The sequence gives the instructions for the production of amino acid that will produce, which in turn determines what traits will be passed on or manifested by that individual.
From the food they intake in different ways such as Plants or other animals such as insects which are their fuel
I think the correct answers are options C and D. Examples of science are a farmer consulting a weather almanac to decide the best time to plant a crop and a<span> drug manufacturer testing a drug to determine its safety. These things require the knowledge on science and its related subjects.</span>