问题描述:
Scientists agree that it will be a long time ___(我们找到了治愈癌症的方法)标准答案是:
before we find the methods of curing cancers我不明白为什么加before在前面?
before we find the methods of curing cancers我不明白为什么加before在前面?
问题解答:
我来补答展开全文阅读