How did people during the zhou dynasty perceive natural disasters such as floods or famine?
they believed it indicated the rulers were not following the mandate of heaven.
they thought it meant that god was angry and sending punishment.
they believed it meant the dynasty would continue to rule with great success.
they thought it indicated the end of times and that they should prepare for death.

What is taking actions to reach your goals

[120 total points] (public health) in one of the largest human experiments ever conducted, in 1954 a randomized controlled trial was run to see whether a vaccine developed by a doctor named jonas salk was effective in preventing paralytic polio. a total of 401,974 children (ages 6–9), chosen to be representative of those who might be susceptible to the disease, were randomized to two groups: 200,745 children (the control group c) were injected with a harmless saline solution (a placebo) and the other 201,229 children (the treatment group t) were injected with salk’s vaccine.what was the point of giving saline solution to the children who didn’t get the vaccine? explain briefly.

A35-year-old woman comes to the ed complaining of chest pressure. she has had such episodes intermittently over the last 5 years, usually when sleeping, but over the last year she has had more frequent severe symptoms that are occasionally associated with severe migraine headaches. the pain is midsternal and is described as pressure that extends as a band around her chest. the ed physician is initially dubious that the pain is cardiac in origin, because the woman has no coronary disease risk factors. an ecg, however, shows 2mm st-segment elevation and inverted t waves in leads v1 through v5 and 1mm st-segment depression in leads ii, iii, and avf. before the cardiologist arrives in the ed, the patient's ecg has returned to normal. this repeat normal ecg is obtained after the administration of aspirin, nitroglycerin, morphine, and oxygen. which of the following is most likely for these findings? - diffuse intimal thickening with focal areas of atherosclerotic narrowing - intermittent thrombus formation and lysis in the left anterior descending artery - intermittent thrombus formation and lysis in the right coronary artery - plaque rupture and thrombus formation in the left anterior descending artery - transiently increased coronary vascular tone in the right coronary artery