conceptual models and physical models.

D. Both (a) and (c).

Physical models can be seen and touched

Models need to be changed as often as deemed necessary by the market. Different types of models need to be changed at different times.

There are various models of Science that are best out of waste. They contain various models of the things that we use in our day to day lives like the tin can lanterns.

Most models are required to be between size 0-4. Fashion models should be 5'8" or taller and meet the following measurements: 34-24-34.