Ⅰ.in time“及时”，指的是不迟到或在提前的时间之前做某事，后面可接不定式或for短语。
Ⅱ.on time“准时”，指按规定的时间或指定的时间做某事，后面不可以跟不定式或for短语。如：
① Joe was just in time for the bud. Joe正好赶上那班汽车。
② They got there on time to see the exhibition. 他们准时到那儿，去看了那个展览。
③ Can you get there in time? 你能及时感到那儿吗?
④ You must always return your library book on time. 你必须总是按时归还从图书馆借的书。
仁爱八上Unit 1 Topic2 Section B
仁爱版八上《Topic 1 You’d better go to see a doctor》ppt课件B
仁爱版英语八上《Topic 1 What hobbies did you use to have》ppt课件
仁爱版英语八上《Topic 2 What sweet music》ppt课件
仁爱版八上《Topic 1 Are you going to play basketball》ppt课件A
仁爱八上Unit 1 Topic 3 Section C
仁爱版八上《Topic 3 The students used live models, didn’t they》ppt参赛课件（含素材文件）
仁爱版八上《Topic 1 Plants and animals are important to us》ppt课件D
仁爱版英语八上《Topic 2 I must ask him to give up smoking》ppt课件
仁爱版八上《Topic 2 I am sure there are no UFOs》ppt课件B
仁爱版英语八上《Unit 2 Keeping Healthy》ppt课件
仁爱八上Unit 1 Topic2 Section C
仁爱八上Unit 3 Topic 2 Section D
仁爱版英语八上《Topic 1 What hobbies did you use to have》ppt课件之三
仁爱版英语八上《Topic 3 Must we do exercise to prevent the flu》ppt课件
仁爱版英语八上《Topic 2 I like country music》ppt课件
仁爱版八上《Topic 1 You’d better go to see a doctor》ppt课件A
仁爱版英语八上《Topic 1 Are you going to play basketball》ppt课件
仁爱版英语八上《Topic 1 What hobbies did you use to have》ppt课件之一
仁爱版英语八上《Topic 3 Which sport will you take part in》ppt课件
仁爱版英语八上《Topic 3 What should we do to fight SARS》ppt课件
仁爱版八上《Topic 2 I am sure there are no UFOs》ppt课件
仁爱版英语八上《Topic 2 Would you mind passing me some water》ppt课件
仁爱版八上《Topic 1 Plants and animals are important to us》ppt公开课课件B
仁爱版英语八上《Topic 1 You’d better go to see a doctor》ppt课件之一
仁爱八上Unit 2 Topic3 Section A
仁爱版英语八上《Topic 3 What were you doing from seven to nine yesterday》ppt课件之三
仁爱八上Unit 1 Topic3 Section A
仁爱版英语八上《Topic 1 Are you going to play basketball》ppt课件之一
仁爱八上Unit 1 Topic 1 Setion C