Answer: D
Explanation: Keeping the pressure constant and increasing the temperature.
If you are looking for a simpler maintenance timeline, oil your machine once after every fifty hours of use, or at the same time you can clean out the lint that may have built up in the machine various books and crannies.
1) gain
(just remember this OIL-Oxidation Is Loss and RIG-Reduction Is Gain)
2) decrease
Copper will have the greatest density, followed by calcium, another metal. Carbon will be the third most dense followed by chlorine, which, as a gas, will be MUCH less dense than the other 3
