When the declining-balance method is used

A.the annual depreciation cost is a fixed percentage of the property value at the beginning of the particular year
B.the annual cost for depreciation is same each year
C.the value of the asset can decrease to zero at the end of the service life
D.the value of the asset decreases linearly with tiime

Oleum is

A.a misture of conc. H2SO4 and oil
B.sulphuric acid which gives fumes of sulphur dioxide
C.sulphuric acid saturated with sulphur trioxide
D.a mixture of sulphuric and nitric acid.