instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
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
answer:
What kind of systems use fluid to transmit pressure and increase force?

question:
Passage: Many genetic disorders are caused by mutations in one or a few genes. Other genetic disorders are caused by abnormal numbers of chromosomes. Answer: genetic disorders
answer:
What type of disorders are caused by mutations in genes or abnormal numbers of chromosomes?

question:
Passage: African Giraffes. Giraffes feed on leaves high in trees. Their long necks allow them to reach leaves that other ground animals cannot. Answer: long necks
answer:
What allows giraffes to reach leaves that other ground animals cannot?