Italics are used for: 1. Numbers represented by letters, general functions and statistical symbols, such as straight line L, rectangle ABCD-A1B1C1D12. Variables in mathematics and physics, and functions that change with variables, etc. , representing scalar letter symbols, such as f (x); x = 1 ^ 3。 Symbols of physical quantities, such as v, s, t 4. A symbol of concentration in chemistry, such as n, M 5. Scientific names in biology, such as Chl.a, chlorophyta 6. Russian letters representing unit codes, such as cm, Ф (diameter) 7. Common Greek letters? ,? Foreign languages, such as French and Latin in the article. Such as: etc. Wait. Nine. The title of the article, the title of the article, the name of the ship, such as Titanic.