Which of the following can reduce biodiversity within a natural environment? a. yucca moths pollinate and feed on yucca plants in the mojave desert. b. red-billed oxpeckers eat ticks off of impalas' coats in the grasslands of east africa. c. non-native american bullfrogs out-compete native amphibians in the tropical andes. d. giant kangaroo rats enrich the soil for plants with their piles of grass clippings in the california grasslands.

4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)