padi IDC dive theory – skills and environment

Q7
It is recommended that a lift bag is used any time an object weighs:
a)    4-7 kg

Q8
Travelling to altitude after diving increases the risk of decompression sickness because?
a)    The pressure in contact with the liquid (blood) is greater than at sea level
b)   The partial pressure of Nitrogen is greater at sea level
c)    The pressure in contact with the liquid (blood) is less than at sea level
d)   There is less oxygen.