法定职责必须为 must carry out all statutory functions and duties

法定职责必须为、法无授权不可为 performing the functions that have been prescribed by law while refraining from acting where the law has not authorized them to act. ; Government must carry out all statutory functions and duties and may not do anything not authorized by law; Anything the law does not authorize is not done; while all duties and functions assigned by law are performed.

必须为整数 Must be an integer

须为零 must be zero

设计必须为人 Design must be for people

必须为零 must-be-zero

传感器须为本安 intrinsically safe

我必须为此道歉 I Must Make an Apology for It

有须毛为缘的 fimbriate