Which is not a piece of evidence that most scientists use to prove the origin of our universe? a. Movement of the galaxies
b. cosmic microwave background radiation
c. presence of hydrogen and helium in the correct percentages
d. The contraction of objects in space

With i really need the correct answer!

The softest and hardest minerals are: softest hardest

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?