This topic examines students' ability to correctly use punctuation marks in modern Chinese, and requires students to memorize the usage of common punctuation marks. The sentence "China and the United States have established a series of bilateral mechanisms" is a relatively complete clause, and the colon after it should be a comma. The content after "I don't know" in sentence C is the object, not the declarative tone. The first question mark should be changed to a comma, and the second question mark should be changed to a period. D sentence "words and pictures in the instruction manual" is in parallel with "on the package" and "on the trademark", and the trademark is included in the picture, so the pause in "words and pictures in the instruction manual" should be replaced by "and class".