Older siblings are smarter

KEY

Question 1

          a) FALSE “ And it's not necessarily being born first that makes the difference”

          b) FALSE “But the reasons behind this trend, {and even whether it's real], have been hotly debated”

          c) TRUE  “Families with low-intelligence children tend to be large“

         d) TRUE  “The work doesn't necessarily show that younger siblings suffer from their lower IQ”

Question 2

       a) You have to be brought up as the eldest child, and not be born first, to be more intelligent than your other siblings.

        b) -being raised as first-born / -time devoted by parents / -tutoring among siblings

Question 3

a)     gathered / (to) gather

b)    prominent

c)     trend

d)   upbringing

e)   evidence

Question 4

a)     First-borns have been proposed to be more intelligent.

b)    Scientists have hotly debated the reasosns behind this trend.

c)     If elder siblings did not spend time tutoring younger borthers and sisters. They would not be smarter.