.— I ‘ll ask our physics teacher to explain Newton’s Second Law of Motion, which she taught us yesterday.— That’s just _______ most of the students haven’t understood.
Some steps have been taken to prevent the forest ____ .
The cleaning workers are on strike to make ____ they are doing an important and necessary job for society.
Every minute he could spare was made use ____ spoken English.
“How much do you ____ for repairing such a pair of shoes?”“Two dollars, sir.”
“Is Jack on duty today?”“It ____ be him. It’s his turn tomorrow.”