APEX Test Prep's US Citizenship Test Study Guide 2021 and 2022: Naturalization Test Prep for all 100 USCIS Civics Questions and Answers [3rd Edition]. Preparing for your test shouldn't be harder than the test itself. To that end, our APEX Test Prep team packs our guides with everything you need. This includes testing tips, straightforward instruction, comprehensive material, practice questions, and detailed answer explanations. All these are used to help study for the US Citizenship exam. Detailed Answer Explanations: Every practice test comes with an in-depth answer key. Miss a question? Don’t know why? These APEX Test Prep explanations show you where you went wrong. Now, you can avoid making the same mistake on the actual exam.