Relacionar Columnas Talking About FunctionsVersión en línea Matching por Logos Sprachinstitut 1 The shelf is bolted to the wall with screws. 2 The airflow is regulated by the valve. 3 The purpose of the wheel is to steer the truck. 4 The purpose of the backup file is to keep our data safe. 5 The vehicle is powered by the engine. 6 The function of the switch is to turn the machine on and off. 7 The bridge is supported by steel pylons. The wheel steers the truck. The switch turns the machine on and off. The backup file keeps our data safe. Screws bolt the shelf to the wall. The engine powers the vehicle. The valve regulates the airflow. Steel pylons support the bridge.