How to combine words?

1, even number, positive even number, such as 2, 4, 6, 8, etc.

2, in pairs: in pairs.

3. disaccharide: The name consists of two monosaccharide molecules. Combine sugars such as sucrose and maltose.

4, double happiness: two happy events (mostly at the same time).

5. Double ring: a kind of firecrackers. The powder is divided into two parts, the lower part is lit and then rings. When it rose into the air, the upper part exploded and sounded again. Some areas are called two kicks or two rings.

6. Two-way: refers to mutual (some kind of activity).

7. Double salary: Double salary.

8. Binary star: Two stars that are very close or have a gravitational relationship with each other are called binary stars.

9. Duet: A dance performed by two people. It can be part of ballet or group dance.

10, double ninth: refers to the eighteenth day after the old custom of marriage, the day when the man gives gifts to the woman.

1 1, double knife:] two knives. Metaphor is two means.

12, Gemini: one of the zodiac signs. Located on the edge of the Milky Way, between Cancer and Taurus, the main bright stars in the constellation are connected into a big rectangle, which can be seen in the winter night sky. The sun passes through it in summer, and summer is just a solar term.

13, Shuangfeiyan: Two swallows fly together. Metaphor men and women often together, inseparable.