?? ??指令: (1)[??][??] ??(??). ??(??).(2)[??]【??】 ??, ?? ???? ?? ??? ???? ???(公文書)? ??.(3)[??]〈??〉 (???) ??.指令代碼;?? ??周期: [??] ??.周期律: [??]〈??〉 (??) ???.周期性: [??] ???.周期表: [??]〈??〉 (??) ????.