In order to be used as a primary key, which of these characteristics must an attribute possess with respect to a single instance of the entity? Select all that apply.

In the lab, which of the following displayed a list of all installed services and included a description of the service, the current state, and whether the service started automatically or manually? a. the services manager b. the applications summary c. the recommended services d. list the safe services list

After you clean an engine with hot water spray, it seems to stall; when it doesn't stall, it's idling noisily. technician a says to check for loose bolts on the flex plate near the torque converter. technician b says to wipe down the spark plug wires and the distributor cap. who is correct? a. technician a b. both technicians a and b c. technician b

You need to design a circuit that implements the functions in the following table: s0 s1 function0 0 a + 10 1 a – b1 0 a + b1 1 a – 1s0 and s1 are 1-bit control inputs to select the function of the circuit. inputs a and b are 4-bitnumbers in 2s complement form. the output is also a 4-bit number in 2s complement form. you are allowed to use only one ttl 7483 4-bit adder to implement all the functions. but anynumber of other components (except the adder) can be used. hint: design a combinational logic circuit to modify the input b and the “carry input” of theadder depending on the control inputs s0 and s1.important: lab grade will depend on the working of the circuit & will be checked of by your labinstructor.1. is the output valid for the following input combinations: a. s0 = 0, s1 = 0, a = 7, b = 3? b. s0 = 0, s1 = 1, a = 7, b = 3? c. s0 = 1, s1 = 0, a = -4, b = -5? d. s0 = 1, s1 = 1, a = -8, b = 6? 2. what is the range of inputs (for both a and b) that will produce the valid output for all the functions?