It's your hw so you really should understand it so you dont have to ask for help so I'll try to explain it the best I can.
1.SD (only one switch occurs, between fluorine and bromide)
2.DD (two things are switched, sulfate and nitrate)
3. D (One compound is broken up into smaller compounds)
4.C (The products of combustion are always h20 and co2)
5.DD (again, two things are switched, bromide and nitrate)
6.SD (In SDR, look for a lone molecule reacting with a compound)
7.S (two smaller compounds become one big compound)
8. D( A big compound is broken up)
9. DD (I think Its DD because two molecules were displaced)*not sure
10.DD(two molecules are displaced, phosphate and hydroxide)