How many times can you subtract 10 from 100?​

Once because next time you would be subtracting from 90

only once the next youd be subtracting 10 to 90

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.