First, the example supplements:

1. My sister is ready to help others and always gives a helping hand to those in need, so she has tasted happiness. My sister is selfless and always gives something to others, so she tastes happiness.

My sister is helpful. She has thin yellow hair, chubby little face, watery big eyes blinking, and the cherry mouth makes people feel sweet, just like a doll.

My sister is helpful and always considerate of others, but she is exhausted by my good sister. I am proud of having such a good sister.

Second, the significance:

1. The supplementary sentence can help us express our views more clearly. Sometimes we may encounter some complicated concepts or opinions when writing. At this time, if we simply describe them, it may confuse readers. If we can add some concrete examples or explanations, it will make it easier for readers to understand our views.

Supplementary sentences can make our article more convincing. In writing, we often need some facts or data to support our views. If you simply list some data, readers may find these data unconvincing. And if we can add some specific explanations or analysis, we can make readers believe our views more.

3. Supplementing sentences can also make our articles more colorful. In writing, if you simply describe some facts or opinions, you may find the article boring, but if you can add some concrete examples or quote some famous sayings, it will make the article more lively and interesting.

4. Supplementing sentences can also make our article more complete. In writing, we often need to explain or analyze a point of view or fact in detail. If the description is simple, readers may feel that the article is one-sided, but if some specific examples or analysis can be added, the article will be more comprehensive.