Though Mary continued working, she kept looking at the clock _____ , thinking of her sick baby in hospital. ( )
A.all the time B.at once C.after a while D.for a moment正确答案A
Though Mary continued working, she kept looking at the clock _____ , thinking of her sick baby in hospital. ( )
A.all the time B.at once C.after a while D.for a moment正确答案A
