Final answer:
Annotation is the critical thinking strategy of marking up a text with arguments, key facts, and questions while reading.
Step-by-step explanation:
The critical thinking strategy of marking up a text with arguments, key facts, and questions while reading is called annotation. Annotation involves actively engaging with the text by highlighting important words and ideas, writing questions and comments in the margins, and flagging different elements like the thesis, evidence, and counterarguments. This strategy helps readers to better understand and evaluate the author's arguments and can be used across various subjects and grade levels.