题目

Many people can’t learn any lessons from the mistakes they’ve made_________they get hurt somehow. A. whether         B. unless            C. if      D. as 答案：B 解析: 略患感冒时，常常刚到呼吸不畅，主要原因是 [     ]A 、鼻黏膜分泌物过多堵塞鼻腔    B 、喉肿胀气体流通不畅 C 、气管分泌痰过多堵塞呼吸道    D 、鼻黏膜肿胀而堵塞鼻腔