Answer is D. Stomach. The stomach is part of the digestive system and not the excretory system. It breaks down food. While the excretory system gets rid of wastes like your bladder does when you use the restroom
It basically means that you skipped slides in what ever you are presenting
You didn’t explain your question correctly so I can’t help you
They instance, "user trial engineer" may refer to a human factors professional who specialists in user trails. Reliability works stress and training as these may relate to human-system and human-computer interaction design.