Written exercises 書面練習
    A Complete these sentences using had to or must have been.完成以下句子，用had to或must have been填空。
    Example：
    He is very tired because he had to get up early this morning.
    He didn't get up early this morning. He must have been tired.
    1 He didn't come to work yesterday. He ______ ill.
    2 He didn't come to the office this morning. He ______ stay at home.3 I don't think she was Austrian. She ______German.
    4 I lost my pen so I ______ buy a new one.
    5 He forgot his case so he ______ return home.
    6 She didn't hear the phone. She ______ sleeping.
    B Write new sentences.
    模仿例句改寫以下句子。
    Example：
    I think she was Danish. (Swedish)
    I don't think she was. She can't have been Danish.
    She must have been Swedish.
    1 I think they were Canadian. (Australian)
    2 I think she was Finnish. (Russian)
    3 I think they were Japanese. (Chinese)
    4 I think they were butchers. (bakers)
    5 I think she was a dentist. (doctor)
    6 I think he was a sales rep. (the boss)
    7 I think she was seventeen. (twenty-one)
    8 I think they were five. (seven)
    9 I think he was seventy-six. (over eighty)
    10 I think she was fifty-five. (under fifty)
    11 I think it was the 17th yesterday. (16th)
    12 I think it was Tuesday yesterday. (Wednesday)
    13 I think it was the 19th yesterday. (20th)
    14 I think it was cheap. (expensive)
    15 I think it was easy. (difficult)
    16 I think she was old. (young)
    17 I think he was ill. (tired)
    18 I think they were listening to the radio. (watching television)
    19 I think she was retiring. (looking for a new job)
    20 I think they were sitting. (standing)
    答案：
    Lesson130
    A
    1 He must have been ill.
    2 He had to stay at home.
    3 She must have been German.
    4 I lost my pen so I had to buy a new one.
    5 He forgot his case so he had to return home.
    6 She must have been sleeping.
    B
    1 I don't think they were. They can't have been Canadian. They must have been Australian.
    2 I don't think she was, She can't have been Finnish. She must have been Russian.
    3 I don't think they were. They can't have been Japanese. They must have been Chinese.
    4 I don't think they were. They can't have been butchers. They must have been bakers.
    5 I don't think she was. She can't have been a dentist. She must have been a doctor.
    6 I don't think he was. He can't have been a sales rep. He must have been the boss.
    7 I don't think she was. She can't have been seventeen. She must have been twenty-one.
    8 I don't think they were. They can't have been five. They must have been seven.
    9 I don't think he was. He can't have been seventy-six. He must have been over eighty.
    10 I don't think she was. She can't have been fifty-five. She must have been under fifty.
    11 I don't think it was. It can't have been the 17th yesterday. It must have been the l6th yesterday.
    12 I don't think it was. It can't have been Tuesday yesterday. It must have been Wednesday yesterday.
    13 I don't think it was. It can't have been the 19th yesterday. It must have been the 20th yesterday.
    14 I don't think it was. It can't have been cheap. It must have been expensive.
    15 I don't think it was. It can't have been easy. It must have been difficult.
    16 I don't think she was. She c an't have been old. She must have been young.
    17 I don't think he was. He can't have been ill. He must have been tired.
    18 I don't think they were. They Can't have been listening to the radio. They must have been Watching television.
    19 I don't think she was. She can't have been retiring. She must have been looking for a new job.20 I don't think they were. They can't have been sitting. They must have been standing.