The research is so designed that once _____ nothing can be done to change it.

Danby left word with my secretary ________ he would call again in the afternoon. 

When he knocked at the door, my mother was busy ____ supper.

—What do you mean ________ saying “The boy is overgrowing”?— I mean that he is tall ________ his age.

—My daughter lived in France for five years and now she's working in a foreign company.—______is no wonder that she speaks such excellent French.