【简答题】Additional social stresses may also occur because of the population explosion or problems arising from mass migration movements-themselves made relatively easy nowadays by modern means of transport.
【单选题】One of the most hazardous conditions a fire- fighter will ever encounter is a backdraft (also known as a smoke explosion). A backdraft can occur in the hot-smoldering phase of a fire when burning is i...
A.
has more oxygen available for combustion.
B.
has more carbon dioxide available for consumption.
【单选题】One of the most hazardous conditions a fire- fighter will ever encounter is a backdraft (also known as a smoke explosion). A backdraft can occur in the hot-smoldering phase of a fire when burning is i...
【简答题】Fuel gases are very combustible and can easily explode. Explosions can occur when a gas leaks from its container and reaches an ignition source, such as an open flame or spark. In the United States, m...
【单选题】One of the most hazardous conditions a fire- fighter will ever encounter is a backdraft (also known as a smoke explosion). A backdraft can occur in the hot-smoldering phase of a fire when burning is i...