In the 20^th century, physicists have made their greatest discoveries about the characteristics of ________ objects like the atom and its parts.

Question

Directions:Each sentence below has a blank space indicating that something has been left out. Following each sentence four words are given. Choose the word that makes the sentence meaningful.

In the 20^th century, physicists have made their greatest discoveries about the characteristics of ________ objects like the atom and its parts. 

(1) infinitesimal 

(2) infinite 

(3) microscopic 

(4) kaleidoscope

Answer 1

In the 20 th century, physicists have made their greatest discoveries about the characteristics of microscopic objects like the atom and its parts.