Answer:
You can use a tea net to separate the Legos and the sand. When you scoop up the sand into the net, the sand will be sifted away because it is smaller than the holes in the tea net. But, the LEGOs are much bigger, so they will remain inside the net.
Primary succession is one of two types of biological and ecological succession of plant life, occurring in an environment in which new substrate devoid of vegetation and other organisms usually lacking soil, such as a lava flow or area left from retreated glacier, is deposited. In other words, it is the gradual growth of an ecosystem over a longer period.
The tailbone is an example of a homologous stucture.
One method I know of is comparing a sample of the rock to other samples which the scientist already knows the age of. I forgot what this method is called but I know it's used by lazy scientists that use other scientist findings like the age of a rock to compare to their own work