please solve complete in 30 minute

24 10 points If the concentration of oxygen gas found in the air-filled pore spaces of a soil is 200 mg/L at a temperature of 25 degrees Centigrade, what would be the DO concentration of the pore waters (assuming equilibrium)? A. 0.75 mg/L B. 5.5 mg/L O O O O C. 7.5 mg/L D. 9.8 mg/L 25 5 points The Safe Drinking Water Act applies to average individual household wells. True False 26 5 points If a meandering (curvy, lots of bends) stream with a gravel and cobble channel bed is re-engineered as a straight, concrete-lined channel, but the channel cross-sectional geometry stays the same, then the depth of flow (stage) for a given discharge magnitude will be lower in it's new, engineered form. True False