The sharks would be characterized as ovoviviparous. This is defined as an animal producing an egg hatched within the body of the parent. This occurs in few fish, snakes, and insects.
Some common elements that are gaseous state at room temperature are:
Oxygen
Nitorgen
Fluorine
Chlorine
Hydrogen
Helium
In addition, all of the elements in group VIII are gases too, they have an octet of electrons (complete outer electron shell) , they're really stable and therefore they're called noble gases. Some examples from group VIII include helium, krypton, xenon etc.
Substance exist as gases in room temperature is due to their boiling point, where is it lower than the room temperature (usually around 25°C). If their boiling point is higher than room temperature, they should exist as either solid or liquid, which is how the majority of the elements in the periodic table is.
Animal extinction, plant extinction
