第11题: [单项选择]下列除哪项外,均为挥发油的通性 A. 与水不相混溶 B. 具挥发性 C. 为油状液体 D. 折光率较高 E. 比重较大 参考答案:E 答案解析:常温下挥发油大多为五色或淡色的透明液体,多具浓烈的特异性嗅味,常温下可自然挥发,不溶于水,而易溶于各种有机溶剂,多数比水轻,多具有强的折光性。
第20题: [单项选择]The pivoting point of a fully loaded vessel with normal trim proceeding ahead at sea speed is(). A. right at the bow B. one-third the length of the vessel from the bow C. one-half the length of the vessel from the bow D. two-thirds the length of the vessel from the bow 参考答案:B