If students were learning about congress or the United States Government, a great project based learning activity would be to write a letter to congress. It promotes collaboration and communication as well as application of the material.
If students are learning about plants and animals or their habitats, they would create questions about the topic, then research those questions and create a presentation. Afterwards they would reflect with the class on their findings and what they learned.
Students learning a new topic in history might be asked to create questions about the topic or may be presented with questions from the teacher. A class discussion will take place where the leader will make sure to clarify, synthesize and restate opinions being discussed. Students need to be able to defend their positioning and statements.