1) In the 1920s Otto Rohwedder designed…
2) In 1938 Lazlo Biro invented …
3) In the 1970s Spencer Silver and Arthur Fry invented…
4) In around 1510 Peter Henlein made …
5) In the thirteenth century Roger Bacon made…
6) In about 1596 Sir John Harrington designed…
A. … the ballpoint pen.
B. … the first glasses.
C. … Post-itÒ notes.
D. … a machine for bakers.
E. …the toilet with a seat and a cistern.
F. … a portable clock.
