A roof system is secured to a roof deck on a building. The passenger compartment monitoring and control system includes an undesirable condition sensor disposed in the interior of the car that detects the undesirable condition. A controller monitoring the radar system may detect a radar blockage when a return signal magnitude is less than a threshold. The broker may also create and distribute samples of the goods, which are created by techniques such as distorting or burdening part or all of a copy of the goods. The channel is formed in the active region directly under the gate, extends to the at least one protrusion, and divides the active region into a first section and a second section.