Add punctuation: In addition to this they are number of reasons accountable for the loss of files from external FireWire hard drives
A: In addition to this, they are number of reasons accountable for the loss of files from external FireWire hard drives.

Add punctuation: International Comparison Leave and Paid Holidays
A: International Comparison: Leave and Paid Holidays

Add punctuation: It should not be difficult to get enough but it is estmated that at the beginning of the last century an average adult person got more than 1000 mg of magnesium a day
A:
It should not be difficult to get enough, but it is estmated that at the beginning of the last century, an average adult person got more than 1000 mg. of magnesium a day.