______ in his studies, he didn't know that all the others had left.
A．Buried B．Burying C．Having buried D．Bury
We had much difficulty __________ home in the snowstorm.
A．walked B．walk C．walking D．to walk
“Be careful, do not stand ___________ to the fire, Jim.” Mrs. Thompson said to her little son.
A．closed B．closely C．close D．closing
Several pages were found _________ when the book _________ me.
A．missing; returned B．gone; was returned to
C．lost; was returned D．disappeared; was returned to
--- How many students are there in your school?
--- There are 2,000 students here __________.
A．first of all B．in all C．after all D．at all
____________ two exams to worry about, I have to work really hard this weekend.
A．As for B．Besides C．With D．As
