Question

fill in the blanks to complete each sentence with the word most appropriate in the context of the sentence.
according to the united nations, in 2012 the of people in the world reached seven billion.
environmentalists are concerned about how our planet can sustain the growing human population with a limited of land and water.
in order to help prevent human overpopulation, scientist benjamin zuckerman favors using tax breaks to encourage families to limit the of children they have.
number amount

Explanation:

First Sentence:

We need to choose between "number" and "amount". "Number" is used with countable nouns (people are countable), while "amount" is for uncountable nouns. So for "people", we use "number".

"Land and water" here refer to the quantity of resources. "Amount" is used for uncountable nouns (land and water as resources are uncountable in this context of quantity available), so we use "amount".

"Children" are countable, so we use "number" (since we count the number of children).

Answer:

number

Second Sentence: