第26题:[单选题]What is the altitude range of ALPHA FLOOR? A. This protection is available from lift-off to 100 ft RA on approach B. This protection is available from lift-off to landing C. This protection is available from 100 ft from lift-off to 100 ft RA on approach 参考答案:A
第27题: [单项选择]DNA变性后,下列哪一项变化是正确的?() A. 对260nm紫外吸收减少 B. 溶液粘度下降 C. 磷酸二酯键断裂 D. 核苷键断裂 E. 嘌吟环破裂 参考答案:B