第4题: [单项选择]It can be inferred from the passage that lighthouses in the Northeast did NOT need high towers because ______. A. ships there had high masts B. coastal waters were safe C. the coast was straight and unobstructed D. the lighthouses were built on high places 参考答案:D 答案解析:[解析] 第二段第三句可知,东北海岸的灯塔一般都建在高处,因此灯塔本身并不高。
第5题: [单项选择]肠溶衣片常用的包衣物料是() A. PVP B. HPMC C. CAP D. PEG E. HPC 参考答案:C