【判断题】在分时和批处理系统结合的操作系统中引入“前台”和“后台”作业的概念,其目的是改善系统功能,提高处理能力。
【单选题】At the time of the earthquake Jeff was still in his office. He ________ to finish a project before he left for the day.
【简答题】He must finish his homework by today. must调到句首
【简答题】If he (finish)______his work on time, he will go for a picnic with his friends tomorrow.
【简答题】引入批处理系统的目的是为了提高 ____________ 。
【简答题】He will come home as soon as he ______ his homework at school. (finish)
【简答题】在分时和批处理系统结合的操作系统中引入了“前台”和“后台”作业的概念,其目的是 。