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

Passage: Transcription takes place in three steps: initiation, elongation, and termination. The steps are illustrated in Figure below . Answer: transcription
Initiation, elongation, and termination are the three steps of what?

Passage: Earth's climate has changed many times. Long warm periods were broken up by ice ages. Over the past 150 years, climate has warmed quickly. Answer: ice ages
What occurs between long warm climate periods?

Passage: Like Earth, the Moon has a distinct crust, mantle, and core. The crust is composed of igneous rock. This rock is rich in the elements oxygen, silicon, magnesium, and aluminum. On the near side, the Moon's crust is about 60 kilometers thick. On the far side, the crust is about 100 kilometers thick. The mantle is made of rock like Earth's mantle. The Moon has a small metallic core, perhaps 600 to 800 kilometers in diameter. The composition of the core is probably mostly iron with some sulfur and nickel. We learned this both from the rock samples gathered by astronauts and from spacecraft sent to the Moon. Answer: core
Like earth, the moon has a distinct crust, mantle, and what else?