【正文】
bus ______ _______ _______.4)我決定先買一杯咖啡,然后再去辦公室。 As I ______ _______ ______ ______ with the other office workers, I ______ _____ _____ ______. was waiting in line heard a loud sound◆ When I got to school, I realized that I had left my backpack at home.◆ By the time I got back to school, the bell had rung.◆ Before I got to the bus stop, the bus had already left.由 when, by the time, before等引導(dǎo)時(shí)間狀語從句時(shí),若描述發(fā)生在過去的事,主句常用過去完成時(shí) (had + 過去分詞 )表示動(dòng)作發(fā)生在過去的過去。4a Make sentences using by the time or before.1. Tim went into the bathroom. Mary got up. By the time Mary got up, Tim had already gone into the bathroom.2. The coffee became cold. I put cream (n. 奶 油 ) in the coffee. __________________________________ __________________________________Before I put cream in the coffee, the coffee had bee cold.3. The teacher collected the math homework. I got to school. __________________________________ __________________________________4. I pleted the work for my boss. The workday (n. 工作日 ) ended. __________________________________ __________________________________By the time I got to school, the teacher had collected the math homework.I had pleted the work for my boss before the workday ended.5. The movie started. I arrived at the cine