1. Who invented Stethoscope ?

Answer: Laennec of French in 1819.

2. Who invented Electron ?

Answer: Thomson. J of Britain in 1897

3. Who invented paper ?

Answer:

Cai Lun

4. Who invented by Electric Lamp ?

Answer: Thomas Alva Edison of U.S.A. in 1879

5. Who invented Printing Press ?

Answer:

Johannes Gutenberg

6. Who invented Morphine ?

Answer: Friderich Sertumer of Germany in 1805

7. Who invented Refrigerator ?

Answer:

Oliver Evans in 1805