Answer: Active volcanoes have a recent history of eruptions; they are likely to erupt again. Dormant volcanoes have not erupted for a very long time but may erupt at a future time. Extinct volcanoes are not expected to erupt in the future.
Explanation: Volcanoes are classified as active, dormant, or extinct.
Answer:
Option a, 
Explanation:
According to Arrhenius concept of acids and bases, acids are those substances which releases H+ in aqueous solution and bases are those which releases OH- in aqueous solution.
Among the given only can release 
in aqueous solution.
LiOH releases 
, therefore it is an Arrhenius base.
and 
cannot releases .
So, the correct option is option a.
Answer:
it would have caused organisms to move in search of food and better conditions.
