ββ:ββ。

γγ:γγ。

δδ:δDelte。

εε:εε。

ζ ζ: Jetta Zeta.

εη:Etaη。

θ θ: the west tower θ.

ι ι: Aiota Iota。

κ κ κ: kappa kappa.

∧λ:λλλλ。

μ μ: seedlings.

ν ν: Anger.

ξ ξ: Cauchy xi.

οο: Omicron, European Michael Wheel.

∏π:π。

ρ ρ: Soft ρ.

∑σ: Sigma.

τ τ: Let τ.

υ υ: Yupu Xilong Upsilon.

φφ:fai Phi .

χ χ: Pool.

ψ ψ: Psy Psi。

ωω:ωω。

Greek letters:

The Greek alphabet originated from the Phoenician alphabet, which has only consonants and is written from right to left. The vowels in Greek were developed, and the Greeks added vowels. Because the Greek writing tool was a wax board, sometimes the first line was written from right to left, and the last line was written from left to right, which became the so-called "cultivated land" writing, and then gradually evolved into all writing from left to right.

The direction of the letters is also reversed. The Romans introduced the Greek alphabet, changed it into Latin alphabet with a little change, and it became popular all over the world. Greek letters are widely used in academic fields, such as mathematics. Cyrillic letters also evolved from Greek letters.

The English word alphabet (letter) comes from the alphabetum in vulgar Latin, and the alphabetum comes from the Greek word α λ φ α β ο ν (transliteration of Beton), which is the synthesis of the first two Greek letters α(Alpha) and β(Beta).