语法与词汇 Through a procedure known as time-sharing, one large computer can be employed (simultaneously) by lots of small users.
【正确答案】 C
【答案解析】at the same time“同时”。ahead of time“提前”；all the time“一直”；in time“及时地”。本题译文：通过共享，这台大型计算机可以同时被许多用户使用。