Which is the best inference? In ancient times there were no.

A. buildings
B. skyscrapers
C. tall structures

D. cities


2. Which is the best clue to question number 1’s answer?

A. Modern building materials make it possible to build such tall
structures.

B. Modern skyscrapers are the tallest building in the world.

C. The only way to make room is to make taller buildings​