Scientists have achieved a major in the search for a cure for cancer is good news for t

问题补充：

Scientists have achieved a major in the search for a cure for cancer, is good news for those who suffer from cancer.

A. breakthrough; what

B. breakdown; which

C. breakup; that

D. breakthrough; which

答案：

A. breakthrough; what

B. breakdown; which

C. breakup; that

(答案→)D. breakthrough; which

解析：考查名词和非限制性定语从句：句意：科学家在癌症疗法上已经有了重大发现，这对于癌症患者是好消息。第一空填A. 或D“breakthrough”突破，B. breakdown;破裂，C. breakup分手，第二空是非限制性定语从句，用which指代前面的句子，选D。