Add punctuation: Should we not concentrate our attention on the very large accidents which are very unlikely but which will result in major damage if they finally should occur
A: Should we not concentrate our attention on the very large accidents, which are very unlikely, but which will result in major damage, if they finally should occur?

Add punctuation: Peter Miller died on July 27th after a long battle with leukemia
A: Peter Miller died on July 27th after a long battle with leukemia.

Add punctuation: Vitamin K is important to the lungs nervous system and vitality
A:
Vitamin K is important to the lungs, nervous system, and vitality.