Question

Which beakers in the model contain solid insoluble substances?

Answer 1

Although the models are not provided, I was able to find them and the beakers with solid present in them are:
1C
2A
2C
3A
3C

This is determined by the fact that the beakers all have a piece of closely packed substance laying at the bottom. This closely packed lattice is characteristic of solid substances, and the fact that they exist in the solution in the solid states indicates that they are insoluble.