题目

experts have found that the disease will lead to a great increase
Experts have found that the disease will lead to a greater increase in the number of sufferers unless seriously when the symptom first appears.
A．treated B．having treated C．be treated D．to be treated

答案是A 求详解 谢谢~

提问时间：2020-12-13

答案

unless 后面接句子: unless they were treated
我们将主语和谓语的助动词省略,就是unless treated.
我们常用的if possible 就是if it is possible 的省略说法.