Hedrovefastandarrivedanhour_____ofschedule.
B
ahead of “提前，预先 ” ，ahead of schedule “比规定时间提前 ”，正合题意。本句意 为“他开得很快， 比规定时间早到了 1 小时。”in advance “ 事先，提前”，后面不跟介词。 in front of “ 在⋯⋯前面 ”，表示位置，所以此处不合题意。
Childrenwhoareover-protectedbytheirparentsmaybecome_____.
Ifhe_____thestorekeeper‘sscissors，hewouldhaveforgottentobuyapair.
Itwasnotuntilshehadfinishedallherwork_____.
Thegirlwhofoundtheringreceivedagenerous_____offivepounds.