1) The first commercially available digital camera, the Dycam Model 1, was introduced in 1990 and had a resolution of 376 x 240 pixels.

2) The word "island" contains two vowels: I and A.

3) The musical "Les Misérables" is one of the longest-running shows in the West End and Broadway, with over 13,000 performances.

4) The Russian Revolution in 1917 resulted in the overthrow of the monarchy and the establishment of a communist government under Vladimir Lenin.