What pair may mean?

Lexical analysis:

double；twofold

English pronunciation: [? d？ bl]

Chinese explanation: double double; Double; Pairing; Pairing; Both; double；twofold

Example:

The concentration of 1% methylene blue used in this study is twice that used in the United States.

The concentration of methylene blue used in this study is 1%, which is twice that of the United States.

Phrases:

1, double layer double layer

2. Double room Double room

3. middle double-story n. building; Deck room

4. Double stars

5, double bed double bed

Extended data

Usage of double:

1 and double as adjectives basically mean "double", and the nouns they modify are generally singular.

2.double is often used to express multiples, followed by nouns, numerals and pronouns. Sometimes the definite article the or possessive pronouns can be used between double and modifier nouns.

Double can also mean "double, double", which can be extended to "very similar people", "double actor" and "double bet in horse racing"

4. It can also refer to "doubles" of tennis. At this time, the plural form is generally used; It can also refer to "winning the second prize" in similar competitions, generally in singular form, preceded by a definite article.