对于下列每一个调度，说明其是否为可串行化调度、冲突可串行化调

对于下列每一个调度，说明其是否为可串行化调度、冲突可串行化调度、视图可串行化调度、可恢复调度，以及是否能够避免级联撤销。

(a) read(T₁,bal_x), read(T₂,bal_x), write(T₁,bal_x), write(T₂,bal_x), commit(T₁),commit(T₂)

(b)read(T₁,bal_x),read(T₂,bal_y),write(T₁,bal_x),read(T₂,bal_x),read(T₁,bal_y),commit(T₁), commit(T₂),commit(T₃)

(c) read(T₁,bal_x), wnite(T₂,bal_x), write(T₁,bal_x), abort(T₂),commit(T₁),

(d) write(T₁,bal_x), rea(T₂,bal_x), write(T₁,bal_x),commit(T₂), abort(T₁)

(e) read(T₁,bal_x), write(T₂,bal_x), write(T₁,bal_x),read(T₃, bal_x). commit(T₁). commit(T₂), commit(T₃)