题目：An if statement usually creates a 2-to-1 multiplexer, selecting one input if the condition is true, and the other input if the condition is false.

解题：

module top_module(input a,input b,input sel_b1,input sel_b2,output wire out_assign,output reg out_always   ); always @(*)beginif (sel_b1==1&&sel_b2==1)out_always =b;elseout_always =a;endassign out_assign=(sel_b1==1&&sel_b2==1)?b:a;endmodule

结果正确：