Unit 3 The internet Period 3 Discovering Useful Structures 课件(共69张PPT+ 讲义）高中英语人教版（2019）必修 第二册

Period 3　Discovering Useful Structures 阅读以下短文，感知加黑部分，并完成练习 Within the next 80 years，our lives may be changed beyond recognition by 3D printing.Many things in our lives ①have already been affected，right down to the food we eat.For instance,3D-printed hamburgers ②have been served to customers in some restaurants in London.But perhaps the most significant success that ③has been achieved to date is in medicine.Human body parts，including a beating heart，④have been made with 3D printing technology.And it is not just humans that are benefiting—in Brazil，a new 3D-printed shell ⑤has been given to a turtle injured in a forest fire. 以上黑体部分均是现在完成时的被动语态，其构成是have/has been done；黑体部分的动词与句子的主语之间是被动关系，表示“……已经被……”。 现在完成时的被动语态 现在完成时的被动语态表示到现在为止某事已经被完成或被做。 运用现在完成时的被动语态时应掌握以下几个方面： 一、现在完成时的被动语态的常用句式 肯定式 主语＋have/has been done... 否定式 主语＋have/has not been done... 一般疑问式 Have/Has＋主语＋been done...？ 特殊疑问式 疑问词＋have/has＋主语＋been done...？ He has been selected to take part in the sports meeting.他已被选中参加这次运动会。 To Tom’s disappointment，his novel has not been published.让汤姆失望的是，他的小说还没有被出版。 Has the date for the next meeting been decided 下次会议的日期已经确定了吗？ How many residents have been invited to the conference？有多少居民受到了参会的邀请？ [即时训练1]　句型转换 A new network has been set up in the neighbourhood. ①否定式：A new network hasn’t been set up in the neighborhood. ②一般疑问式：Has a new network been set up in the neighborhood ③对in the neighborhood提问：Where has a new network been set up 二、现在完成时的被动语态的3个用法 1．表示被动的动作在说话之前已经完成，强调过去的动作对现在造成的影响或产生的结果，通常与already，yet，never，recently等副词及时间状语so far，by now，up to/till now，since等连用。 The database has already been updated. 数据库已经被更新了。(现在可以使用新的数据库了) 2．表示一个被动的动作或状态从过去开始一直持续到现在，并可能继续持续下去，常与for或since等引出的时间状语(从句)连用，或用于由how long引出的句子中。 Financial problems of the company have been discussed for nearly two hours. 公司的财务问题已经被讨论了近两个小时了。(可能还会继续被讨论) 3．用在时间或条件状语从句中，表示将来某时以前已完成的动作。 We’ll leave at three if our work has been finished by that time.我们将于3点离开，如果到那时我们的工作已经被完成。 [即时训练2]　用现在完成时的被动语态改写句子 ①They have built many houses in the village in the past few years. →Many houses have been built(by them) in the village in the past few years. ②You can’t go home before you has settled the matter. →You can’t go home before the matter has been settled (by you)． 三、使用现在完成时的被动语态的6点注意 1．与一般过去时的被动语态的区别。一般过去时的被动语态所表示的动作或状态与现在的情况没有联系，而现在完成时的被动语态则强调与现在的情况有联系。 The book was lent to a ... ...