What is life-continuum? In the book Path Of Purification It talks about


  The explanation of the meaning here( " talking about the five jhana mastery mostly mastety if Adverting " ) is this. When he emerges from the first jhána and first of all adverts to the applied thought, then, next to the adverting that arose interrupting the life-continuum, either four or five impulsions
  impel with that applied thought as their object. Then there are two life-continuum
  [consciousnesses]. Then there is adverting with the sustained thought as its
  object and followed by impulsions in the way just stated. When he is able to
  prolong his conscious process uninterruptedly in this way with the five jhána
  factors, then his mastery of adverting is successful. But this mastery is found at
  its acme of perfection in the Blessed One’s Twin Marvel (Paþis I 125), or for others on the aforesaid occasions. There is no quicker mastery in adverting than
  that.


I'm having trouble understanding what they mean here. What iis life-continuum? It said in brackets consciousness so it's disrupting consciousness of the jhana object? What i guess they mean is once you come out of jhana use applied thought to focus on the things that intruped that jhana then once you have "applied" applied thought move to focus on the objects with sustain thought once you can do this uninterrupted you mastered adverting?
life-continuum is Bhavanga-citta. It's the filler thought moment/moments between every 2 thoughts/experiences. It keeps you from dying when the senses cannot provide an object to the mind. When you are in dreamless sleep, your mind mostly has Bhavanga-cittas. 

It's the first thought moment in your life and the last thought moment of the previous life. It is a resultant thought moment, thus Karmicly neutral. For humans and above, it's always a result of good Karma. For hell-beings, it's a result of bad Karma.