My sister is a journalist. She write articles.

Ответ: My sister is a journalist. She writes articles.

1. My sister is a journalist. She write articles. - Исходное предложение.
2. My sister is a journalist. She writes articles. - Исправленное предложение. (В Present Simple с местоимениями he, she, it глагол приобретает окончание -s)

Ответ: My sister is a journalist. She writes articles.