a. drop 表示 “使落下、使掉落”，是及物动词, 带宾语： He dropped the bag. b. fall 表示 “掉下、跌倒”，是不及物动词，不能带宾 语。 He fell down the stairs and broke his leg.
3. Forest fires are often caused by broken glass or by cigarette ends which people carelessly throw away. 森林火灾时常由破碎的玻璃或人们随手扔掉的香烟头引起。 be caused by… 由…所引起 His death was caused by a high fever. 他的死亡是由高烧引起的。 The accident was caused by the drunk driver. 事故是由酒后驾车的司机造成的。 cigarette ends 烟头 which 引导的是 定语从句
Listen and answer questions
1. Have firemen put out the big fire? 2. What are forest fires often caused by? 3. Who discovered the cause of the bid fire? 4. Where did the snake wind itself?
★cause • 1）V. 引起 • cause sth : 引起（麻烦） • 粗心导致事故 • Carelessness causes accidents. • 骄傲使人失败 • Pride causes failure
carelessness
★ examine • 1）v. 仔细观察,检查,调查 • 消防队员检查了森林的每一寸土地。 • The firefighters examined every inch of the forest. • 2）v. 诊查 • 医生仔细的诊察了病人。 • The doctor examined his patient carefully • 3）v. 考试,测试 • examine students in English • n. exam 考试=examination
5. They were also quite sure that a cigarette end did not start the fire. 他们还十分肯定火灾也不是由烟头引起的。
be sure 确定 Be sure to sweep the room clean. 一定要把房间打扫干净。 I am sure you would get along very well with him. 我相信你一定会跟他相处得很好。 One thing is sure; he can't have gone far. 有一点是肯定的，他不可能走得很远。 She is sure to pass the examination. 她一定会通过考试。 start a fire＝cause a fire 引发火灾
9. A bird had snatched up the snake from the ground and then dropped it on to the wires. 一只鸟把蛇从地上抓起来，然后把它扔到了电线上。于 是蛇就缠住了几根电线。 snatch v. 抓 The man snatched her purse and ran.
• solve v. 解决,解答,回答 =work out
solve a problem • • • • • 我们必须解决经济危机。 We must solve the economic crisis. n. solution 解决,解答 花费了很长时间才找出解决方法。 It took a long time to find the solution
现在完成进行时
构成：have/has been+doing 含义： 1）表示从过去某时开始一直持续到现在的 动作，并且还将持续下去。 2）表示在说话时刻之前到现在正在进行的 动作。
与现在完成时的区别
I have been writing a book. 我一直在写一本书。 （动作还将继续下去） I have written a book. 我已经写了一本书。 （动作已经完成
1. At last firemen have put out a big forest fire in California. 消防队员们终于扑灭了加利福尼亚的一场森林大火。 at last（终于，到底）表示经过一番努力之后。 put out可以表示“扑灭”、“熄灭”、“关掉” Please put the light/ fire out. 请把灯关掉／把火灭掉。 Far water does not put out near fire. [谚]远水救不了近火。
• remain 1）v. 留下,剩下,遗留 • 大火之后，我的房子里什么也没剩下。 • After the fire, nothing remained in my house. • 要做的事还很多。 2）v. 仍是,保持不变 • 他保持沉默。 • He remained silent.
★ wire n. 金属线，电线 • telephone wires 电话线 • Electric wires 电线 • wireless adj. 无线的
辨析
• • • • • • • • • snatch 迅速而有力(粗鲁地)抓住,抢 snatch a chance grab 抓,抢,抢夺,抓住(热切而拼命地) grab sth from sb/ grab sth from sth grasp 1) 抓住或咬住,抓紧 grasp a chance 抓住机会 2)掌握 grasp a language hold 抓住,握住,托住
6. This morning, however, a fireman accidentally discovered the cause. 然而今天上午，一个消防队员偶然发现了起火的原因。
discover 发现（偶然发现某个已经存在的东西） They discover that the new teacher is very strict. 他们发现新来的老师非常严格。 He was surprised to discover that his best friend had turned traitor. 他惊讶地发现他最好的朋友竟成了叛徒。 I do not discover that until I go to pay. 我去付钱的时候才发现。
4. Yesterday the firemen examined the ground carefully, but were not able to find any broken glass. 昨天，消防队员仔细查看了地面，但未能发现碎玻璃。
be able to 能够 ；be not able to 没有能够 The doctors were not able to treat this disease. 医生治不了这种病。 I am sorry, I am not able to help you. 对不起，我无法帮助您。 I was not able to get in touch with you yesterday. 我昨天无法和你联络上。 他现在没办法接你的电话。 He is not able to take your call at the moment. 我无法回答您的问题。 I am not able to help you with your questions.
★ accidentally adv. 意外地,偶然地 • n. accident 事故,意外 • a car accident • adj. accidental 意外的,偶然的 • 意外死亡 • an accidental death
★ remains • 1）n. 剩余物,残余物 • 残汤剩饭 • the remains of a meal • 2）n. (古建筑等物)遗址,废墟 • 圆明园遗址 • the remains of Yuanmingyuan • 3）n. 遗体,遗骸 • 毛主席的遗体被保存在水晶棺材里。 • The remains of Chairman Mao were kept well in a crystal coffin.
wound为wind的过去分词。wind在这里不表示“蜿 蜒”，而表示“卷在……上”、“缠绕”，常与around ／round连用： Did you wind this piece of wire round the tree? 是你把这根铁丝缠在树上的吗？
8. In this way, he was able to solve the mystery. The explanation was simple but very unusual. 就这样，他解开了起火之谜。解释很简单，却异 乎寻常。 Solve v. 解决 solve the problem 解决问题
★ power • 1）电力，动力 • electric power 电力 • water power 水力 • 2）力,能力 （自然的体力、智力） • His power is failing. • 他的体力在衰退。 • 3）权力, 势力 within one’s power beyond one’s power
7. he noticed the remains of a snake which was wound round the electric wires of a 16,.000-volt power line. 他发现了缠绕在16，000伏高压线上的一条死蛇。 the remains表示“尸体”、“残骸”，必须用复数形式
Lesson 53