Around, hollow rock that is lined with mineral crystals is known as a
a. mineral rock
c. vein
b. geode
d. none of the above

The correct answer is letter B, geode.

Geodes are round, hollow rocks that are lined with mineral crystals. The opposite of geodes are called nodules. Agates, jaspers, and chalcedony are nodules  because they do not have hollow cavities the way that geodes do.

May consider a group  g=({0,1},+)g=({0,1},+)where  ++  will work as the xor operator like we work in boolean algebra. note here, that ‘00’ and ‘11’ are not the usual 0 and 1 that we work with everyday. the elements are  called  ‘00’ and ‘11’ and  may not mean  zero (nothing) and one (single). ‘00’ is the identity for the given binary operator +, meaning that any element operated with ‘00’ gets us that element itself.  for a set  ss  in  g′g′  having more elements than just  {0,1}{0,1}  the values for  a+b∈sa+b∈s, such that  a∈s,b∈sa∈s,b∈s, have to be first defined, only then can you determine the value of  1+11+1. the answer could possibly have been  22  if oanswer is25,000

Answer glacier terminus;