Describe how deep oceanic currents are formed.

Explanation:

Ocean currents can be caused by wind, density differences in water masses caused by temperature and salinity variations, gravity, and events such as earthquakes or storms. Currents are cohesive streams of seawater that circulate through the ocean.

They are caused by: the sinking and transport of large masses of cool water giving rise to the thermoahline circulation. The earths rotation also influences them!

Explanation:

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.

it would lead to upper respiratory infections and pneumonia.