Mosquitoes get their food by sucking other animals blood, sometimes giving it disease. what type of symbiosis is this.

The symbiosis between mosquitoes and the microorganisms responsibles of disease is endosymbiosis.

Explanation:

Mosquitoes usually have different microorganism inside their digestive tract. When mosquitoes suck other animals blood, their transmit those microorganisms (frequently parasites) to the animal. In these cases mosquitoes are called vectors, organisms that have microorganisms (endosymbionts) inside but do not suffer any consequences, they only act as a house for the endosymbiont.  

d.) circle motion requires a force to give it a centripetal acceleration.