Do want your students to understand how to use evidence to support a claim? That's the goal of this project.
Students first find evidence to support a known fact (such as the Earth is round). Then they run their list of facts by you and you identify holes in their logic. Once they have compiled enough research, they then write an argumentative essay proving the claim.
Then students repeat the process for an unverifiable claim (such as global climate change is caused by humans). They must go into the same level of detail as before.
The topics provided in the worksheet are suggestions. The document is editable so that you can alter it to be more appropriate for the age group or the culture of your community.