I believe true because the Precambrian is the first geologic time, going back 4600-570 years ago, meaning it should contain the earliest of things.
<span>Rice pudding would be an example of a heterogeneous mixture.
A heterogeneous mixture means that different constituents of a mixture can be identified. Rice pudding consists of rice suspended in a cream. It is possible to identify the grains of rice and the creamy part of the mixture.
A homogeneous mixture looks the same throughout--you cannot identify individual parts or ingredients. The parts of a homogeneous mixture are said to be uniformly distributed. Rainwater and air are examples of homogeneous mixtures.</span>