1) Robert Downey Jr. is an American actor known for his portrayal of Iron Man in the Marvel Cinematic Universe. He has also starred in films such as "Sherlock Holmes," "Chaplin," and "Tropic Thunder," and has received critical acclaim and commercial success for his performances.

2) The first computer mouse was invented by Douglas Engelbart in 1964 and consisted of a wooden shell and two metal wheels.

3) The first successful consumer digital camera, the Apple QuickTake 100, was released in 1994 and had a resolution of 640 x 480 pixels.

4) Tiramisu, an Italian dessert, is a layered concoction of ladyfinger biscuits soaked in coffee, mascarpone cheese, and cocoa powder. It originated in the region of Veneto and is known for its creamy and indulgent flavors. Tiramisu has become a popular dessert worldwide and is often enjoyed at the end of a meal or as a sweet treat during special occasions. It combines the richness of coffee, the sweetness of mascarpone, and the texture of sponge fingers for a delightful experience.