The discovery of the cosmic microwave background was important because:. a. it established a firm center of the universe.
b. it was experimental verification of a prediction from the Big Bang theory.
c. its detection was a major advance in microwave testing.
d. it proved that astronomy at radio wavelengths was possible.
e. it showed the universe must be closed, with more than the critical density here.

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

Which of the choices below is one of the primary gases found in the atmosphere? a. helium b. carbon dioxide c. nitrogen d. argon

What is the average speed of a car that travels 40mph for 1 hour and 60 mph in another hour will mark brainliest