Unit 3. № 38. ГДЗ Английский язык Enjoy English 10 класс Биболетова. Помогите найти значения

Find in the text from Ex. 37 the words and expressions in bold that mean the following:
 
a)     a long period of time when there is little or no rain and crops die
b)     a group of people who live by killing wild animals and finding food but do not by growing crops
c)       very great or extreme
d)       as a reaction
e)       to use all of something and not have any left
f)        with a lot of people living close together
g)       cities with no people in them
h)     extremely important because it has a major effect on something
i)        to stay alive despite difficulties
j)        immediately
k)     to create a situation in which something fails or stops existing