-Hello! Is Mr. John in the office?-Yes. But I'm sorry. He is busy __________ and can't speak to you.
A person _______ a foreign language must be able to use the foreign language _______ all about his own.
.The wallet _______ several days ago was found _______ in the dustbin outside the building.
.Lessons _______ easily were soon forgotten.
The ground is _______ with _______ leaves.
The library's study room is full of students _______ for the exam.