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

Q: Passage: Transcription takes place in three steps: initiation, elongation, and termination. The steps are illustrated in Figure below . Answer: transcription

A: Initiation, elongation, and termination are the three steps of what?
****
Q: Passage: For feeding, the insect head contains one pair of lower jaws and two pairs of upper jaws. Insects have also evolved a wide range of specialized mouthparts for eating certain foods. You can see some examples in Figure below . Answer: two pairs

A: How many pairs of upper jaws do insects have?
****
Q: Passage: Check to see that gas lines are made of flexible material so they do not rupture. Any equipment that uses gas should be well secured. Answer: flexible material

A:
Gas lines should be made of what so they do not rupture?
****