题目

There ______ (乌云密布) when I went to school. 答案：【答案】were dark clouds【解析】句意：当我到达学校的时候，天气乌云密布。该句是there be句型，乌云dark clouds，根据从句部分可知该句是一般过去时态，主语是复数形式，故系动词用were，故答案为were dark clouds。 Accidents are very common and nearly everyone has had        one． A． at least          B． at last         C． at most           D． at first