1. It takes a long time as well as many experts working together to compile an encyclopedia.
    编一本百科全书，不仅要花一段长时间，还要有许多专家一起工作才行。

2. In 1928 some porpoises were photographed working like beavers to push ashore a waterlogged mattress.
    1928年，有人拍摄到了海豚像海狸一样把浸透水的床垫推上岸的情景。

3. It is no use inviting the politician or the professional or business man, who has been working or worrying about serious things for six days, to work or worry about trifling things at the weekend.
    同样，对于为严肃的公务操劳或烦恼了6天的政界人士、专业人员、商人来说，在周未再让他们为琐事而动脑子和忧虑也是无益的。

4. In addition to national AIDS programs, working together internationally has begun.
    除了每个国家的艾滋病防治计划外，国际合作也已经开始。

5. In the mid-1870s, French artist Frederic Auguste Bartholdi was working on an enormous project called Liberty Enlightening the World, a monument celebrating US independence and the France-America alliance.
    19世纪70年代中期，法国艺术家弗里德里克·奥古斯特·巴托尔迪正在设计一个大项目，名为"自由照耀世界"。这是一座庆祝美国独立和美法联盟的纪念碑。

6. For them the working hours are never long enough.
    对他们来说，工作时间总不会太长，

7. Fatigue and poor performance may begin to appear in the second stage of deficiency, when not enough iron is present to form the molecules of blood protein that transport oxygen to the working muscles.
    到了缺铁的第二阶段，就会出现疲倦和力不从心，此时体内已没有足够的铁来形成血蛋白分子，将氧输至运动着的肌肉。