【正文】
or five hours. A: How long did Sam skate? B: He skated for four hours. A: … B: … 時(shí)間狀語 : 1. for +一段時(shí)間 2. since +過去的時(shí)間點(diǎn) 3. since +一般過去時(shí)的句子 表示動(dòng)作從過去某一時(shí)間開始一直延續(xù)到現(xiàn)在或離現(xiàn)在不遠(yuǎn)的時(shí)間。其動(dòng)作是否繼續(xù)下去,由上下文而定。這個(gè)時(shí)態(tài)多用于延續(xù)性動(dòng)詞。 現(xiàn)在完成進(jìn)行時(shí) 構(gòu)成: have / has been + +…… Summary Homework 187。Make a survey about how long your family members have been doing something and give a report next class .