88. Despite the hardship he encountered, Mark never__gave up pursuing knowlege_（放弃对知识的追求）
89. Scientists agree that it will be a long time before we find the methods of curing cancers（我们找到治愈癌症的方法）
90. Production has to be increased considerably to keep pace with the constantly incre 2009年12月英语四级答案翻译部分 标签：
