材料周围的磁场强度H增大然后降低到零时，零件内磁感应强度B却不恢复到零。用来定义H恢复到零时的B值的术语

The students in our school each ___ an English dictionary.

The students in our school each ___ an English dictionary.

The students in our school each ___ an English dictionary.

The students in our school each ___ an English dictionary.

The students in our school each ___ an English dictionary.

The students in our school each ___ an English dictionary.

The students in our school each ___ an English dictionary.

If I had known that, I ___ so.

My father, together with some of his old friends, ___ there already.

My father, together with some of his old friends, ___ there already.