Use reasoning to lead to the answer of the following question:
Before computers or cellphones a dictionary was an important tool for teachers and students in the what?\nOptions:\n- manual\n- shelf\n- explain meaning of words\n- table\n- classroom
 Reasoning process:
User
Classroom is a room in which a class of pupils or students is taught. Before computers or cellphones a dictionary was an important tool for teachers and students in the Classroom. Therefore, the final answer is classroom.
Assistant