The immune system responds differently to pathogens that infect intracellularly, such as viruses, than it does when responding to extracellular pathogens, like most bacteria. The MMR vaccine is a combination vaccine used against three viruses. Our bodies develop immunity through a series of steps that result in the activation of cytotoxic T cells against virally-infected cells. Place the following steps for T cell activation in the correct order. First Step to Last Step:1. A helper T cell binds to the MHC-II protein of an infected dendritic cell.2. The dendritic cell secretes IL-12 to differentiate the helper T cell into a type 1 helper T cell.3. Dendritic cells infected with the virus migrate to lymph nodes.4. Activated cytotoxic T cells undergo clonal expansion. The type 1 helper T cell secretes IL-2 to activate the cytotoxic T cell.5. Activated cytotoxic T cells self-stimulate and leave the lymph node.6. A cytotoxic T cell binds to the MHC-I protein of an infected dendritic cell.

Mantle convection  is the slow  creepingmotion of earth's solid silicate  mantle  caused by  convection  currents carrying  heat from the interior  to the planet's surface.[1][2]  the earth's surface  lithosphere, which rides atop the  asthenosphere  (the two components of the  upper mantle), is divided into a number of  plates  that are continuously being created and consumed at their opposite  plate boundaries. accretion occurs as mantle is added to the growing edges of a plate, associated with  seafloor spreading. this hot added material cools down by  conduction  and  convection  of heat. at the consumption edges of the plate, the material has thermally contracted to become dense, and it sinks under its own weight in the process of  subduction  usually at an  ocean trench.[3]this subducted material sinks through the earth's interior. some subducted material appears to reach the lower mantle,[4]  while in other regions, this material is impeded from sinking further, possibly due to a phase transition from  spinel  to  silicate perovskiteand  magnesiowustite, an  endothermic reaction.[5]the subducted oceanic crust triggers  volcanism, although the basic mechanisms are varied. volcanism may occur due to processes that add buoyancy to partially melted mantle causing an upward flow due to a decrease in density of the partial melt.secondary forms of convection that may result in surface volcanism are postulated to occur as a consequence of intraplate extension[6]  and  mantle plumes.[7]it is because the mantle can convect that the  tectonic plates  are able to move around the earth's surface.[8]mantle convection seems to have been much more active during the  hadean  period, resulting in gravitational sorting of heavier molten  iron, and  nickel  elements and  sulphides  in the core, and lighter  silicate minerals  in the  mantle.

Cuz i said so. which gives it to b

Of the cold they can survive in the cold