00355nam a22001457a 4500003000700000005001700007008004100024082002300065100001100088245003100099250001700130260003400147300000800181650002000189MPLRDC20220104143316.0210129b ||||| |||| 00| 0 eng d a448.8 RMYD v.1 c.2 a不详 a无线电问与答汇编c a一版一刷 ab人民邮电出版社c1981 b平 a无线电工学