The following belongs to which class of lever?
(i) The Physical balance
(ii) A see-saw
(iii) An oar of a boat
(iv) Human-arm
(v) Pliers Tools
(vi) A claw-hammer
(vii) Rowing of a boat
(viii) A fire tongs
(ix) Sugar tongs
(x) A pair of scissors
(xi) Wheel barrow
(xii) Nut cracker
(xiii) Lemon crusher
(xiv) Knife
(xv) Fore-arm
(i) Class I (ii) Class I (iii) Class II(iv) Class III (v) Class I (vi) Class I(vii) ClassII (viii) Class III (ix) Class III(x) Class I (xi) Class II (xh) Class II(xii) Class II (xiv) Class III (xv) Class I