To use the drop-down menu to complete the sentence, follow these steps:
1. Identify and locate the drop-down menu in the question or document you are working on. Look for a downward arrow (∨) symbol or the word "select" or "choose."
2. Click or tap on the drop-down menu to open it.
3. Look through the available options in the drop-down menu.
4. Select the option that best completes the sentence. In this case, the appropriate option to select would be "dictatorships."
5. After selecting the option, the drop-down menu will typically close, and the selected option will replace the original prompt or incomplete sentence.
After completing these steps, the sentence should read: "In the late 1900s, conflict broke out in Central American countries such as Guatemala and Nicaragua as people fought to overthrow dictatorships."