Open the brackets. Use the Past Simple or the Past Continuous. Sam (read) the rules when the other students (come).

Let's analyze the sentence: "Sam (read) the rules when the other students (come)." We need to use either Past Simple or Past Continuous.

The correct form is: Sam was reading the rules when the other students came.

Explanation: The action of reading was in progress when another action (the other students arriving) interrupted it. Therefore, we use Past Continuous for 'read' and Past Simple for 'come'.