Classify the following as voluntary actions and involuntary actions. Sneezing, throwing balls, heart beats, writing.

Based on the provided list, I can classify the actions as follows:

Voluntary actions:

Throwing balls: This action requires conscious intent and control over the muscles involved, making it a voluntary action. It involves a deliberate choice and effort to perform the action.

Writing: Writing is typically a voluntary action as it requires conscious control over the muscles involved in holding the writing instrument and forming the letters. It is a deliberate act that is initiated and controlled by an individual.

Involuntary actions:

Sneezing: Sneezing is generally considered an involuntary action. It is an automatic reflex triggered by irritation or stimulation of the nasal passages. While it is possible to hold back a sneeze to some extent, the act of sneezing itself is typically beyond conscious control.

Heartbeats: Heartbeats are involuntary actions controlled by the autonomic nervous system. The heart contracts and relaxes rhythmically without conscious effort or control. While certain activities or emotions can influence heart rate, the basic functioning of the heart is not under conscious control.

It's worth noting that the classification of an action as voluntary or involuntary can vary depending on the context and individual circumstances. Some actions may have elements of both voluntary and involuntary components.