牛津译林Unit4 Grammar课件.ppt

Unit 4 A good read Grammar On a visitThey ________ prepare for it before the trip.But They __________ take everything with them. have to don’t have to be sick she ________ see a doctor when she gets sick.Her mother ____________ look after her at home.She _______________ have lessons at school. has to has to doesn’t have to get lostHe __________ stay there and wait for help when getting lost.He _______________ be afraid . has to doesn’t have to On a visitbe sick get lostThree situations Gulliver was tied to the ground. He had to lie on the ground.Grandma is ill. She has to see the doctor.We use have to when the situation makes something necessary.She doesn’t have to worry about herself.He didn’t have to shout at the tiny men.The doctor says she’s OK We _________ keep quiet in the library! must We ______ smoke in the library! mustn’t We ________ take photos in the library! mustn’t We _______ put the waste into the dustbinWe ________ throw litter about ( 乱扔垃圾) must mustn’t We use must when the speaker feels that something is necessary.We use must not to say that something is not allowed(不被允许) Gulliver is tied to the ground. So he must run away.Study is very important. So we must study hard.He mustn’t lie on the ground.We mustn’t talk in class. At schoolWe ________ listen to the teacher carefully in class！We _________ talk to others in class !We __________ work hard!We __________ throw litter about in the school !mustmustn’tmustmustn’t In the streetPeople _______ play in the street.People ________ wait for the green traffic lightsPeople _________ go across the road when the traffic light is red !People _________ spit (吐痰) all around!mustn’tmustn’tmustmustn’t Go out for a visit We ________ talk loudly in the public places .We ________ wait in the queue when there are lots of people.we ________ write everywhere when travelling .mustn’tmustn’tmust Com