Why was it important to allow all the investigation materials to assume room temperature before beginning the experiment?

The temperature is kept at room temperature and mostly preferred to be constant, so that the temperature does't be a variable factor effecting the accuracy of experiment.

Temperature is kept constant to take it as a control factor, so that experimental results are not effected by such outside factors. Such control variables are important in experiments as they minimize the influences from outside.  

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

the must be sensory neurons.  

hope its .