时间与频率表达 — 英语选择题
题目
Mary's school starts at 8:00 a.m. She usually leaves home 25 minutes earlier to walk to school, but last Friday she got up late and left home only 10 minutes before class began. How many minutes later did she leave home last Friday than usual? A. 10 minutes B. 15 minutes C. 25 minutes D. 35 minutes