Four metals were kept in contact with each other. The table below shows the initial temperature of the metals. Metal Initial Temperature
А
30 °C
B
42 °C
С
25 °C
D
16°C
From which metal will heat flow into all the other metals?
Metal A
Metal B
Metal C
Metal D

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.

i think that the answer is c