Here’s the correct matching of the actions with the energy forms:
1). Putting slices into the toaster - Mechanical (the action of placing bread into the toaster involves physical movement)
2). Plugging in the toaster - Electrical (this action connects the toaster to an electrical power source)
3). The toast becoming crispy and golden - Heat (the toaster uses electrical energy to produce heat, which cooks the bread)
4). Hearing the toast pop up - Sound (the popping noise occurs when the toast becomes toasted and the mechanism releases it)