Apple

Apples were a common fruit on Earth.

The Fourth Doctor once claimed that he hid up a tree and dropped apples on Isaac Newton's head. (DW: The Pirate Planet) Newton remained upset about that, as his nose bled for three days afterward. (BFA: Summer)

While possessed by the Mara, Tegan dropped apples upon Aris in order to get his attention. (DW: Kinda)

While at Shangri-La, a young boy handed the Seventh Doctor an apple. Melanie Bush repeatedly prevented him from eating it. (DW: Delta and the Bannermen)

Whilst visiting the Worldsphere, the Seventh Doctor met a parachute that designed apple trees in its spare time. (NA: The Also People)

Following his regeneration, the Tenth Doctor found an apple in a dressing gown that had been provided for him by Jackie Tyler. (DW: The Christmas Invasion)

Following his tenth regeneration, the Eleventh Doctor thought he wanted an apple but didn't like it. Amelia Pond disliked apples when she was young, until her mother began carving happy faces into them. She gave an apple with a carved happy face on it to the Doctor, who promised to keep it for later. After travelling forward 12 years, the Doctor proved his identity to now-grown Amy Pond by showing her the same apple, still fresh. (DW: The Eleventh Hour) He later enjoyed on apple he found on a prison ship. (DW: The God Complex)

At some point in the far future the word "apple" was used in the prevailing calendar system, as the year 5000000000 was known to the locals as 5.5/Apple/26. (DW: The End of the World)