Answer: iron (oxides of iron)
Explanation: manganese nodules usually contain layers of iron and manganese oxides in a concentric arrangement and are called polymetallic nodules.
Answer:
The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.
Explanation:
Number of hours worker exposed to xylene = 
The concentration of xylene in the workplace =
The worker is inhaling air at a rate of
.
Amount xylene inhaled by worker in an hour :
= 
Amount xylene inhaled by worker in 320 hours:

1 μg = 0.001 mg
Amount xylene inhaled by worker in 320 hours = 11.520 mg
1 day = 24 hours
Amount xylene inhaled by worker in 1 day:

Assuming 70 kg body mass, the chronic daily intake of xylene :

The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.
A because if something happened to that organism then the organism relying on it will either go extinct or just die out due to starvation
E
Water is the only polar compound so I guess that must be odd one out. I’m sorry I’m of no actual help.