Multiple choice

Directions: Fill in the blank with correct preposition.

The sun is the main source ________ energy.

  1. of

  2. in

  3. off

  4. on

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The phrase 'source OF' is the correct preposition to use when indicating origin or cause. 'The sun is the main source OF energy' shows that energy originates from the sun. This is a fixed collocation in English.