Answer:
scientist Antonie Van Leeuwenheok
The appearance of fossils would the the answer.
Although there has been some scientific debate about what fossil strata should mark the beginning of this period, the "International Geological Congress" determined that the Cambrian period was approximately 543 million years ago of which the first appearance in the fossil record of worms that made horizontal burrows was discovered.
The bulk of the heart rests on the side of the body. On the left side
Im not knowing of this subject but i'm sure your answer is C.) Patterns
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