2)they haven`t seen each other since last may. (自去年五月起，他们一直没见过面。)

　　turn在句中做名词，意思是“转折点”。since the turn of the century意思是“自本世纪初(或上世纪末)。”

　　1)he hasn`t written home since the turn of the year. (自去年底以来他还未给家里写过信。)

　　2)at the turn of the two centuries， they had many hearty wishes for their family。(在两个世纪交替之时，他们对家人有许多衷心的祝愿。)

　　7.in the face of all these facts， it seems senseless for countries to continue destroying their rainforests。

　　介词短语in the face of 意思是“面对”。如：

　　1)they didn`t give up in the face of adversity. (面对逆境，他们没有放弃。)

　　1)he kept his head in the face of flattery. (面对奉承，他保持镇静。)

　　it seems senseless for sb. to do sth. (对于某人来说做某事是愚蠢的)

　　it是形式主语，动词不定式真正的主语。这种句式我们已多次碰到过。如：

　　1)it is important for us to get into contact with them as soon as possible。(我们尽快与他们取得联系是很重要的。)

　　2)it seems useless for you to argue further with him. (你再跟他争辩下去似乎是毫无意义的。)

　　在动词continue的后面既可以用动词不定式也可以用动名词，意思都是“不间断地做某事”。如：

　　1)it is necessary for us to continue to learn things in life. (我们在生活中不断学习是必要的。)

　　2)he continued doing his homework. (他继续做家庭作业。)

　　8.…the government often have no choice but to turn a blind eye。

　　have no choice but to do sth. (别无选择，只能…)，如：

　　1)i had no choice but to take the last train to go home. (我别无选择，只能乘末班火车回家。)

　　2)they had no choice but to accept the term. (他们别无选择，只能接受这个条件。)

　　turn a blind eye (to sth。) (对…视而不见)，类似的表达不有turn a deaf ear to sth.，如：

　　1)he turned a blind eye to the messy room (他对凌乱的房间视而不见。)

　　2)the manager turned a deaf ear to the customers` complaints about the poor service。(顾客报怨服务太差，经理对此置若罔闻。)