人教版高中英語必修2教案Unit 4 Wildlife protection
if the agent (the performer of the action) is important, use “by.” for example: tim wilson wrote the flight to brunnswick in 1987. the flight to brunnswick was written in 1987 by tim wilson. only verbs that take an object can be used in the passive. the following chart includes sentences changed from the active to the passive in the principal tenses. active passivetime reference they make fords in cologne. fords are made in cologne.present simplesusan is cooking dinner. dinner is being cooked by susanpresent continuousjames joyce wrote dubliners. dubliners was written by james joyces.past simplethey were painting the house when i arrived. the house was being painted when i arrived.past continuousthey have produced over 20 models in the past two years. over 20 models have been produced in the past two years.present perfectthey are going to build a new factory in portland. a new factory is going to be built in portland.future intention with going toi will finish it tomorrow. it will be finished tomorrow.future simple2. passive verb formation the passive forms of a verb are created by combining a form of the “to be verb.” with the past participle of the main verb. other helping verbs are also sometimes present: “the measure could have been killed in committee.” the passive can be used, also, in various tenses. let’s take a look at the passive forms of “design.”tense subjectauxiliarypast participle singular plural present the car/cars is are designed. present perfect the car/cars has been have been designed. past the car/cars was were designed. past perfect the car/cars had been had been designed. future the car/cars will be will be designed. future perfect the car/cars will have been will have been designed. present progressive the car/cars is being are being designed. past progressive the car/cars was being were being designed. iv. reading and identifyingsince you are clear about passive verb formation, go back to page 26 and scan the text for all the examples of the present progressive passive voice. our fur is being used to make sweaters like yours.she was being watched by an excited elephant.…now try to put the following sentences into the present progressive passive voice. ▲ they are producing this new drug.▲ antelope is looking at her.▲ they are killing us for the wool.