Fill in the gaps with the correct form of the verbs provided :

(a) Alva Edison was (be) an American scientist in the 19th century.

(b) He possesses (possess) a scientific aim.

(c) Even in his boyhood he showed (show) great interest in science.

(d) This interest led (lead) him to tremendous success in course of time.

(e) He made (make) many of the great inventions of the world.