Please help
I need help on the first one
Answer:
The BOD5 for this sample is 5 mg/L
Explanation:
The BOD5 takes into consideration the difference between the initial DO and the final DO divided by the fraction of the sample tested in a 300 mL BOD flask. The problem states that the sample was directly placed in a BOD bottle so we assume that the volume used was 300 mL of the water sample. The fraction of water is 1 (300/300).

BOD5 = (10-5)/1
BOD 5 = 5 mg/L
<span>When the strength of the rock exceeded it suddenly breaks causing an earthquake </span>
Hello! Fossil fuels are NOT renewable resources. A is out. Burning fossil fuels does produce emissions. B is our. Oil and natural gas does not exist in unlimited quantities, so C is out. However, they are the easiest fuels to make in large amounts, which is why a lot of them are use, despite limited quantities. The answer is D.
<span>Mercury's distance at inferior conjunction is 0.61 AU
Looking at a table of orbits, Mercury has an orbital distance of 0.39 AU. So the inferior conjunction will be:
1 AU - 0.39 AU = 0.61 AU</span>