What are the materials for seven-character couplets?

The characteristics of seven-character couplets are as follows:

1, Part I: Welcome guests by the Spring Festival; Part II: I like to take January as my wedding day.

2. The first part: Mei Daichun gave birth to Liu Qing; Bottom line: Louyuren likes apricot flowers.

3. Shanglian: Zhongyang Willow Flying Parrot; Bottom line: Flowers, the moon and the breeze welcome the phoenix.

4. The first part: Double Star Cowgirl peeks at Han Yin; Bottom line: hibiscus on the ice reflects rosy clouds.

5. The first part: Han Yin looks at the crossing; Bottom line: Jin Feng, Wan Li, Peng Fei, etc.

6. Shanglian: Han Yun Bridge becomes Niudu; The second part: the flute on the spring platform leads the phoenix to fly.

7. Shanglian: Guiyuan Yueming Golden House; Bottom line: the blue sky is warm and fragrant.

8. The first part: Purple clouds blow the moon, item; Bottom line: Cui sleeves dance in the wind, colorful love.