1. overhead projector/ very reliable tool/used/display images/ screen/or/wall.

An overhead projector is a very reliable tool used to display images onto a screen or wall

2.It/used/be/feature/both/classrooms/business meetings.

It used to be the feature of both classrooms and business meetings

3.technology/overhead projector/very simple/ compared/that/modern LCD projector.

Technology of the overhead projector is very simple compared to that of the modern LCD projector

4. They/ good facilities/displaying images/videos/classrooms.

They have good facilities for displaying images and videos in the classrooms