第4题: [单项选择]______ you are leaving tomorrow, we can eat dinner together tonight. A. For B. Since C. Before D. While 参考答案:B 答案解析:since作“既然,由于”讲,相当于now that。例如:Now that we have plenty of time,we might as well take a leisurely walk
第18题: [单项选择]熔模在铸圈内距离圈的内壁、圈的顶端的要求正确的是() A. 距内壁至少3~5mm,顶端8~10mm B. 距内壁至少3~5mm,顶端3~5mm C. 距内壁至少8~10mm,顶端3~5mm D. 距内壁至少1~2mm,顶端3~5mm E. 距内壁至少3~5mm,顶端1~2mm 参考答案:A