1. alternative n ．替换物an alternative to sth. 代替某事物的办法 / 方案 There are some alternatives to our plan. 有几种方案可以代替我们的计划。 have no alternative but to do sth. 除做某事外别无选择He had no alternative but to go there alone. 他别无选择 , 只好一个人去那儿。Explanation2. You must be aware that it's here that we've found evidence of some of the earliest people who lived in this part of the world. 想必你们知道 , 正是在这儿我们找到 了居住在世界这个部分最早人类的证据。 a. You must be aware that… 主句后接由强调句和定语从句组成的宾语从句。 must 是作为情态动词表示肯定推测 , 译作“一 定 , 肯定”。只用于肯定推测。 对现在或将来事实推测，用 “ must do” 。 You must be hungry after a long walk ． 走了很长的路 , 你一定很饿。 对正发生或进行的事进行推测 , 用“ must be doing” 。 The light is on. He must be doing his homework now ． 灯亮着 , 他一定正在做作业。 对过去的事进行推测 , 用“ must have done” 。 The ground is wet. It must have rained last night. 地是湿的 , 昨晚一定下雨了。 此时 , 应注意反意疑问句的构成。如果句中有表示过去的时间状语 , 反意疑问句用“ didn’t+ 主语” ; 如果句中无表示过去的时间状语 , 反义疑问句用 “ haven’t/hasn’t+ 主语”。 He must have arrived here last night, _________? 他一定昨晚就来这儿了 , 不是吗 ? He must have arrived here, ____________? 他一定来这儿了 , 不是吗 ?didn’t hehasn’t he b. aware adj ．意识到的 , 知道的。通常用作表语。 We should be aware that a lot of animals are becoming endangered ． 我们必须清楚地认识到许多动物正濒临灭绝的危险。be aware of sth. 知道；意识到 Though most smokers are aware of the dangers of smoking, they won't given up. c. it’s here that we’ve… 是强调句 , 其基本句式是 It is (was)+ 被强调部分 +that (who)+ 句子其他部分。此结构强调的成分仅限于主语 , 宾语和状语。 It was your...
