Answer:
high frequency sound waves
Explanation:
The fetal cardiac activity emits signal that comprises of high frequency sound waves. This signal is received only when it is converted into a fetal heart rate tracing via computer. These signals are traced through transducers and are shown on the external monitor.
to help your audience understand what you are talking about more
Answer: Double blind clinical trial
Explanation:
The situation that is seen here is double blind clinical trail in which neither the participant nor the practitioner knows who is receiving the treatment.
This is used to prevent biasing in the experiment which is caused due to demand characteristics or placebo effect.
Here, in this situation the dog handlers and the experimental observer both were blinded to identify the breath sample.
The answer is B.Start running in hilly areas or trails. Hope this helps!