Unlike humans that draw air in with the aid of a muscular __, frog lungs need air to be pumped into them like balloons. This is called __ breathing.

Write a paragraph at least 5 sentences “why all vaccinations should be mandatory”

The spermists believed that: the male made the only hereditary contribution to the offspring the male and female traits were blended in the offspring the female made the only hereditary contribution to the offspring the male and the female made equal contributions to the next generation

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic