单选题 Which one of the following may be best used to describe the flexible system?

【正确答案】 A
【答案解析】[试题分析] 本题测试的是对句意的理解。
[详细解答] “The system has proved an almost total success wherever it has been tried．”从这句话中我们可以看出这一系统是卓有成效的。