第28题: [单项选择]The English language contains a(n) ______ of words which are comparatively seldom used in ordinary conversation. A. altitude B. latitude C. multitude D. attitude 参考答案:C 答案解析:[解析] C项multitude意为“大量”，a multitude of words意为“大量词语”。A项 altitude意为“高度，海拔”；B项latitude意为“纬度”；D项attitude
第36题: [单项选择]The main idea of this passage is ______. A. a new rule for all airlines B. the defects of electronic devices C. a possible cause of aircraft crashes D. effective safety measures for air flight 参考答案:C 答案解析:本题问及全篇的主旨。文章主要谈论的是在飞机上使用便携式电子设备可能是引起空难的一个原因。因此，答案是C项。
