Directions: Sentences of a paragraph are given below in jumbled order. Arrange the sentences in the right order to form a meaningful and coherent paragraph.

A. Penicillin is one of the most useful drugs invented by man.

B. First scientists and then ministers of governments were interested in it.

C. With its help we can heal wounds caused by bacteria which cannot be otherwise healed.

D. To begin with, very few people knew of this wonderful discovery or its uses.