Tobe____forthecorporateshareholder'sprogram,youmusthavebeenworkinghereforatleastthreeconsecutiveyears.

The little girl is ignorant _____ the basic rules of English grammar。

As far as she is concerned, one piece of music is very much like

Themanagergaveherhis_____thatthecomplaintwouldbeinvestigated.

Edisontestedmorethanonethousandmaterialstoseeiftheycould_____electric;currentandglow.