单项选择题
A.1个 B.2个 C.3个
A.L IRS ON DC;L IRS ALIGN;L IRS FAULT) B.L IRS NO DC;L IRS DC FAIL;L IRS FAULT) C.L IRS ON DC;L IRS DC FAIL;L IRS FAULT) D.L IRS ON DC;L IRS DC FAIL;L IRS ALIGN)