‘Never’ or ‘not’? ‘Support’ or ‘protect’? ‘Promote’ or ‘maintain’? Should I say ‘never’ or ‘not,’ ‘support’ or ‘protect,’ ‘promote’ or ‘maintain’?

‘Never’ or ‘not’? ‘Support’ or ‘protect’? ‘Promote’ or ‘maintain’? Should I say ‘never’ or ‘not,’ ‘support’ or ‘protect,’ ‘promote’ or ‘maintain’? I guess the first given choices are the only acceptable ones.

1. A great childhood will (never, not) be complete without playtime.
2. Government organizations will always (support, protect) public health.
3. Let us encourage everyone to (promote, maintain) a healthier nation.