It's strange to cross the bridge with others, but you can't see it in rainy days and you can't throw it away in sunny days.

The riddle means: there are strange things that you can cross the bridge with, but you can't see them in rainy days and you can't shake them in sunny days. This is the shadow.

Shadows only exist in sunny days. Sunny days follow you everywhere, and the rain disappears.

Extended data

Riddle:

1, hung on a red fruit stick, wrapped in sugar, tastes good (a foodie)-answer: sugar-coated haws.

2, two people come to the game, the rope around the railing, waving leather gloves, to see who is the champion (playing a sports event)-answer: boxing.

3, don't look at the pile of grass, inside the casserole. Drink two bowls a day and the illness will be driven away. (Take medicine)-Answer: Chinese herbal medicine

4, beauty under the moon (hit a plant)-answer: epiphyllum ("beauty under the moon" is another name for "epiphyllum")

5, thin and black-hearted, wearing colorful clothes. Piano, chess, calligraphy and painting are different. Sharpen your head to help you. (type something)-answer: pencil