The answer would be nodding.
First class lever refer to a lever on which the resistance exist in one one side of the fulcrum and an effort is made on the other side you can't get a reaction unless something else causes a reaction.
Answer:
See the answer below
Explanation:
The sympathetic and sympathetic nervous systems make up the autonomic nervous system, regulating involuntary functions. The first acts in situations of fight or flight, for example in an accident of self-actions such as: increased heart rate, pupil dilation, relaxes airways, among others. Neurotransmitters are released: adrenaline and norepinephrine. The parasympathetic system performs antagonistic functions by activating in relaxation situations: it decreases heart rate, contracts pupils, constricts airways. Acetylcholine is released as a neurotransmitter.
Is it multiple answer?? Because if so I would pick b and d