1 1
1 1 English eleven, pronunciation: English [Levin], USA [Levin].

Example:

Charles I ruled for eleven years. ?

Charles I ruled for eleven years.

We then went to Paris and stayed there for 1 1 day. Then we went to Paris and stayed there for 1 1 day.

note:

1 1 (11) is a natural number and a positive odd number between 10 and 12. Mathematically, 1 1 is the smallest cyclic non-unit prime number; In number theory, 1 1 is a higner number.

Chemically, 1 1 is the atomic number of sodium; Musically, 1 1 is the album name created by China band NAND gate; In other fields, 1 1 is Yao Ming's jersey number, which stands for Singles' Day, the hero of anime novels and so on.

1 1 is the smallest prime number among odd numbers, prime numbers and two digits, and the atomic number of Na. When we count from 0 to 10, another cycle starts from 1 1.