1) What is Section 1 trying to teach the recipient?

The critical period for development, when exposure to disease prenatally can have the most devastating effects of growth, is

On a certain portion of an experiment, a statistical test result yielded a p-value of 0.18. what can you conclude? 2(0.18) = 0.36 < 0.5; the test is not statistically significant. if the null hypothesis is true, one could expect to get a test statistic at least as extreme as that observed 18% of the time, so the test is not statistically significant. if the null hypothesis is true, one could expect to get a test statistic at least as extreme as that observed 82% of the time, so the test is not statistically significant. 0.18 > 0.05; the test is statistically significant. p = 1 - 0.18 = 0.82 > 0.05; the test is statistically significant.

The medium that carries message signals from senders to receivers of communication is