What's the answer to this: Which of the following best describes what the pie chart shows? A.
Changes in human activities can help reduce greenhouse gas emissions.
B.
Methane emissions can be reduced by using natural gas and petroleum systems.
C.
Methane emission can be decreased by creating more landfills.
D.
The amount of methane in the atmosphere does not depend on human activities.

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)