To measure how much stuff is in a specified volume of a substance,
scientists use

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

b is the correct answer

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.