【句型3】The early climbers were looking for the easiest way to the top, because the summit was the prize they sought, especially if it had never been attained before. (Lesson 3) 【译文】早期登山者所寻找的是通往山顶的最方便的途径，因为顶峰，尤其是仍未被人征服过的顶峰，才是他们寻求的目标。 【讲解】先讲述一事实，再用because引出原因，最后用especially引出一种特殊原因。
