A microscope is to see smaller things that you can’t see and it is a really good tool.
Scientists use fossils to study earth history by identifying the fossil and what era it came from. By knowing what era the fossil came from and what location it was found, scientists can make assumptions about the earth formation at that time.
Answer:
The correct answer is "motor unit - motor neuron".
Explanation:
Motor unit and motor neuron are related terms, however they could not be used interchangeably because a motor unit is not comprised only of a motor neuron. A motor unit is made of a motor neuron, skeletal muscle fibers and neuron's axonal terminals. Therefore motor unit is a more broadly term, and is referred to the units that coordinate the contractions of single muscles.
