S Your new gas furnace may have been installed in one of two. ways, as a direct-vent (2-pipe-Fig. 2) application or as a. non-direct vent (1-pipe-Fig. 3) application. S In a direct-vent (2-pipe) application,your furnace uses air. from outside the home for combustion and ventsflue gas to the. outdoors.
For the biological concept, see Anti-predator adaptation. A defence mechanism is an unconscious psychological mechanism that reduces anxiety arising from unacceptable or potentially harmful stimuli. Sigmund Freud was one of the first proponents of this construct.
What is Thaad anti-missile defence system and why is China against it. (BLOOMBERG) - A US missile defence system being deployed in South Korea to counter North Korea is rubbing China the wrong way. The Terminal High Altitude Area Defence system, known as Thaad, is supposed to help South Korea protect itself from a North Korean military attack.