Section 2 Notes to difficult sentences from 1.So accomplished navigators were able to use it to plot their positio ns．熟练的领航员就能够用它来确定自己的位置。句中 accomplished 是形容词，意思是“优秀的，熟练的”，作定语修饰其后的名词 。Accomplished 的用法 如下：已完成的; 已达到的： accomplished facts 既成事实； 学识渊博的, 技术高超的, 有成就的 ： an accomplished cook 厨艺精湛的厨师，Judy is accomplished in English teaching. 茱蒂擅长英语教学； 有教养的, 优雅的： an accomplished lady 才女2.On a clear day especially during the summer the sailors could use the sun overhead at midday to navigate by．在晴朗的日子，尤其是在夏天，水手可以使用正午头顶的太阳来引导他们航行。句中 to navigate by 作目的状语， 修饰谓语动词，其中的 by 是介词，它的逻辑宾语是前面的 the sun。 类似的例句有： I have no topics to write about.He found some pens to write with. He is not the person to get along with.3.Sea birds could be used to show the way to land when it was nowhere to be seen．看不到陆地的时候，可以利用海鸟来定位通向陆地的方向。句中 used 后面有一个停顿。to 到 land 作目的状语。句中 when 引导的是时间状语从句，修饰说明主句谓语动词。4. The number of knots that were counted during a fixed period of time gave the speed of the ship in nautical miles per hour．一定时段得出的绳节数显示航船的海哩时速。句中 that were counted during a fixed period of time 是定语从句，in nautical miles 和 per hour 都是状语。5. Later, when seamen began to use the compass in the 12th century they could calculate longitude using complicat ed mathematical tables．后来到了十二世纪海员开始使用指南针的时候，他们就能够借助复杂的数学表格计算出航行的经度了。using complicated mathematical tables 是现在分词短语作状语，表示手段。更多例句：The boy sat in front of the farm—house cutting the branch. 那男孩坐在农舍前，削树枝。（伴随）...
