(a) List the three main classes of meteorite and describe how they can be distinguished on the basis of their principal constituents.
(b) Name the main technique that is most commonly used to link specific meteorite types with asteroid type. Support your arguments with at least one suitable example.
(c) What are calcium-aluminium-rich inclusions (CAIs)? Describe the three competing theories for their origin, and briefly explain the two main techniques that scientists employ to distinguish between these theories. (About 100 words)
(d) Describe the role of the proposed ‘x-wind model' in the formation of planetary systems around low-mass stars, such as our own Sun.