下列哪些建筑应设置消防车登高操作场地（）

A.商业区
B．娱乐区
C．住宅区
D．宗教区

A.小于或等于3mm
B．大于3
B.大于7mm且小于或等于45mm
D．大于45mm

A、always @(*) case (state) S0: begin out = 0; if (in) next_state = S1; else next_state = S2; end ……
B、always @(*) case (state) S0: begin if (in) next_state = S1; else next_state = S0; end ……
C、always @(*) case (state) S0: begin if (in) begin next_state = S1; out=1 end else next_state = S0; end ……
D、以上答案均不正确