单选题 When (imaginable) scientists (first) suggested the possibility that one person (could speak) directly to another (over) a long distance, few people took them seriously.
【正确答案】 A
【答案解析】改为imaginative。本句要表达的是“富于想象力的科学家”。imaginative富于想象力的。imaginable可想象的，想象得到的。