—Why was he unhappy yesterday? —A letter from home ______ an attack of homesickness.
She was scared _______ stay outside after dark because she was scared _______ being robbed.
. I don’t like such a person _______ often lies before your face.
_______ is known to us all that the old scientist, for _______ life was hard in the past, still works hard in his eighties.
They urged the students _______ the work on time.
In the reading room, we found her _______ at a desk, with her attention _______ on a book.