Which two statements are true about a system? 1. a system is a group of objects analyzed as one unit. 2. energy that moves across system boundaries is conserved. 3. there’s only one way to define the boundaries of a system. 4. all systems are made by humans.

Technician a says that in a fully charged orifice-tube system, the accumulator 3.temperature will be higher than the orifice tube temperature. technician b says that in a properly operating air-conditioning system, the inlet to the compressor should be cool and the outlet from the compressor hot. who is correct? a. technician b b. technician a c. neither technicians a nor b d. both technicians a and b 4. it's 90 °f in the shop with high humidity. what pressure will be shown on the high-side pressure gauge (ac system on)? a. at least 350 psi b. 10 to 50 psi c. 210 to 290 psi d. 40 to 140 psi 5. technician a says that leaking components are usually repaired rather than replaced. technician b says that a replacement o-ring can take care of a leak found at a joint. who is correct? a. technician a b. neither technician a nor b c. both technicians a and b d. technician b 12. technician a says that a system should be recharged with refrigerant until the condenser temperature is equal to the ambient temperature plus 100°f. technician b says that a system should be recharged with the type and amount of refrigerant found on the vehicle's under-hood sticker. who is correct? a. both technicians a and b b. technician b c. technician a d. neither technician a nor b 14. the majority of heat that the cooling system receives from the engine is a. recycled back to the engine. b. wasted. c. directed to the passenger interior. d contaminated air. 18. a schrader valve is able to open only when a. the service cap is removed. b. a special tool is used to disconnect the valve. c. the system has been evacuated. d. an internal depressor seals the connection 19. two technicians are discussing recycling specifications for refrigerant. technician a says that refrigerant oil with 5,000 parts per million (ppm) does not fall within specifications. technician b says that air can only have a maximum of 330 ppm. who is correct? a. both technicians a and b b. technician b c. neither technicians a and b d. technician a 20. two technicians are discussing refrigerant removal. technician a says that all refrigerant must be captured. technician b says that you can vent refrigerant into the atmosphere as long as it contains moisture. who is correct? a. neither technician a nor b b. technician a c. technician b d. both technicians a and b

The equation 24x2+25x−47ax−2=−8x−3−53ax−2 is true for all values of x≠2a, where a is a constant.what is the value of a? a) -16b) -3c) 3d) 16

The smokey mountains have over 2,100 miles of rushing mountain streams and rivers that flow through the park. in each mile lives a diverse community of native fish, amphibians, insects, and larvae, some of which are found only in the southern appalachians. park managers and scientific researchers test many factors such as fish populations, the watersheds and water tests to determine a) too many lizards are present b) the water quality of the stream c) rainwater is running into local streams d) if visitors to the park are overstaying their welcome