An adjustable bench adapted to support a human body during exercise and capable of engaging an auxiliary rack assembly is provided. In one embodiment, a synchronous flash memory is disclosed. Each of the measuring modules can be selectively coupled to the clock by means of the coupler to provide a measuring function associated with the coupled module in accordance with time data provided by the clock. Such arrays may be employed to detect a presence andor concentration changes of various analyte types in a wide variety of chemical andor biological processes. Each cluster may have high level nodes corresponding to the plural hierarchies but only those dependent nodes from the plural hierarchies whose transaction identifiers correspond to that of the cluster.