Question

20．这不但残忍，而且对环境有害．
This is not only cruel，but also harmful to the environment．．

Answer 1

分析 but also harmful to the environment．

解答 答案：but also harmful to the environment．
表示不仅…而且用not only…but also，这里的主谓共一个this is，表示对…有害用be harmful to，后加the environment环境，故答案是but also harmful to the environment．

点评 not only…but also主要用于连接两个对等的成分；若连接两个成分作主语，其后谓语动词与靠近的主语保持一致．Not only the students but also their teacher is enjoying the film．不仅学生们在欣赏这部影片，他们的老师也在欣赏这部影片．