Given a scientific passage and an answer, generate a question for the given answer.

[EX Q]: Passage: Hydraulic car lifts also use fluid to transmit pressure and increase force. The lifts are used to raise cars, which are very heavy, so mechanics can work on them from underneath. Controls in airplanes use fluids to transmit pressure and increase force so a flick of a switch can raise or lower heavy landing gear. To see animations of hydraulic systems such as these, go to URLs:. Answer: hydraulic systems
[EX A]: What kind of systems use fluid to transmit pressure and increase force?

[EX Q]: Passage: 16.3 Circulatory and Respiratory Systems Animal respiratory systems are designed to facilitate gas exchange. In mammals, air is warmed and humidified in the nasal cavity. Air then travels down the pharynx and larynx, through the trachea, and into the lungs. In the lungs, air passes. Answer: nasal cavity
[EX A]: In mammals, air is warmed and humidified in what?

[EX Q]: Passage: Mollusks have a hard outer shell. There is a layer of tissue called the mantle between the shell and the body. Answer: mantle
[EX A]:
What is the layer of tissue between the body and shell called?