Unit 8 learning a foreign language
[點撥]at…a level意為“以……水平”又如：consultations at cabinet level 內閣閣員間的磋商[點撥]at…a cost 以……為代價、以……的價格 eg.1. to sell sth at cost 照成本賣 eg.2. the battle was won at (a) great cost in human lives. 犧牲了許多士兵的性命才換來的這場戰役的勝利。 又如固定搭配：at all costs 不惜任何代價，無論如何 at the cost of犧牲，喪失 eg: he saved his son from drowning, but only at the cost of his own life. 他救了他兒子的命：幸免于溺死，但卻犧牲了他自己的命。 …it is also possible that some of them may fall behind in their studies.一些學生有可能在學習上會落到后面。[點撥]it is possible that…為固定句型，其中possible也可以用likely替換，意思為“有可能……”。此句型還可用sb be likely to do sth…句型替換。但不可以說sb be possible to do sth. eg: it’s likely/possible that he will do very well. 他有可能會干得很出色。[點撥]fall behind意為“落在后面” eg: soon he fall behind in the race.比賽不久，他就落在了后面。 he didn’t want to fall behind in his studies.他不想在學習上落到了別人的后面。grammar虛擬語氣（the subjunctive mood）表示說話人所說的話不是事實，而是一種假設、愿望、懷疑或推測。虛擬語氣主要用于條件從句、讓步從句和名詞性從句中。（1） 虛擬語氣在條件從句中的用法：條件從句條件從句的謂語形式主句的謂語形式
表示現在情況if i(you, he /she, we, they) +動詞過去式should/would/could/might+動詞原形
表示過去情況if i(you, he /she, we, they)+had+過去分詞should/would/could/might+have+過去分詞if i(you, he /she, we, they)+動詞過去式
表示未來情況if i(you, he /she, we, they)+should+動詞原形should/would/could/might+動詞原形if i(you, he /she, we, they)+ were to +動詞原形根據下面例句進一步理解：① 與現在事實相反：if i were you, i should do it in another way. 如果我是你的話，我會用另一種方法做。② 與過去事實相反：if i had not studied hard , i would have failed in the exam. 假如我學習不那么刻苦，就不會通過那次考試了。③ 與將來事實相反：if you missed(were to miss/should miss)the film tonight, you would feel sorry for it.假如今晚錯過了這部電影，你將會感到遺憾的。