be without
Another word for "lack of interest" is apathy or indifference. These both basically refer to a person who is uninterested, unresponsive or impassive. Another word to describe this sort of person could also be perfunctory.
Lack, want,
incommunicado
Inaction??
lack dearth
Another word for energy is heat.
lacking skill
Harsh truth
Lazyness
Mechanical energy!:)
Mechanical energy!:)