第34题: [单项选择]It seems oil {{U}}leaves{{/U}} from this pipe for some time. We'll have to take the machine apart to put it right. A. had leaked B. is leaking C. leaked D. has been leaking 参考答案:D 答案解析:[分析] 时态应用
本句意为:油管漏油好像有一段时间了,我们必须拆开机器排除故障。题干第2句表示将要采取的措施,意味着第l句话“漏油”(leak)的动作发生在过去某一时间,并且持续到现在为止仍