Multiple choice

Directions: Choose the best answer to fill in the gaps.

Infectious diseases are those which are caused ____ an invasion of the body ____ organisms from outside.

  1. through / with

  2. by / by

  3. over / through

  4. in / without

  5. upon / within

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

 Caused by an invasion and by organisms from outside.