Classify the following reaction in one of the reacation type studied in this unit.
(1) `CH_(3)CH_(2)Br+HS^(-)rarrCH_(3)CH_(2)SH+Br^(-)`
(2) `(CH_(3))_(2)C=CH_(2)+HCIrarr(CH_(3))_(2)C CI-CH_(3)`
(3) `CH_(3)CH_(2)Br+HO^(-)rarrCH_(2)=CH_(2)+H_(2)O+Br^(-)`
(4) `(CH_(3))_(3)C-CH_(2)OH+HBrrarr(CH_(3))_(2)CBrCH_(2)CH_(2)CH_(3)+H_(2)O`

Explanation

(1) Nucleophilic substitution
(2) Electrophilic addition
(3) `beta` - Elimination
(4) Nucleophilic substitution & rearrangement