Why are there no samples of rocks from the early Precambrian era? O A. They have undergone metamorphosis.
O B. They are buried under sediment.
O C. All of them formed under volcanoes.
O D. All rocks were molten in that time period.

Imagine that a mouse has white fur because of a mutation in its dna. which of the following conclusions can be drawn

Select the correct answer from each drop-down menu. in an experiment, dr. travis examined the effects of calcium intake on osteoporosis, a condition that causes an increased risk of bone fractures. the amount of calcium is variable. the risk of bone fractures .

The response is the basis for vaccination. primary secondary tertiary none of the above