A. combination B. collaboration C. connection D. collection 参考答案:B 答案解析:短语in collaboration with作“与……合作[合著),与……勾结”讲,例如:She wrote the book in collaboration with her sisters
第31题: [单项选择]X线表现为食管下端光滑的鸟嘴样狭窄者为( ) A. 腐蚀性食管灼伤 B. 食管癌 C. 食管平滑肌瘤 D. 食管静脉曲张 E. 贲门失弛缓症 参考答案:E