unit 1 (a) 参考答案： i. a) 1. twice 2. differences 3. hardly 4. interviewer 5. health b) 6. milk 7. translate 8. grade 9. junk 10. program ii. 1. always 2. often 3. hardly ever 4. sometimes 5. never iii. 1. c although 表示"仍然"，不能和but同时使用。2. b 注意用了once还要加上冠词。 3. a exercise在这里是动词，第三人称单数加s。4. d 提问频率用how often。 5. a start with... 是"以......开始"的意思，固定搭配。 iv. 1. of course 2. look after 3. on weekends 4. go to the movies 5. kind of v. 1. went 2. are swimming 3. helps 4. were 5. playing  unit 1 (b) 参考答案：一、翻译： 1. is good for 2. try to 3. what sports 4. in good health 5. start, with 二、句型： 1. look after 2. how often 3. doesn't go 4. go to the movies 5. how many hours 三、完形： 1-5 acbbc   6-10 adbab 四、书面表达参考范文： my sundaytoday is sunday. i get up at half past seven. at noon i go to the zoo with my mother. after a short rest, we go shopping in the market. in the afternoon, i go to the playground to play football with my friends. we have a good time there. after supper, i stay at home to do some reading. i read a book. its name is red star over china. 单元练习参考答案unit 1 how often do you exercise?ⅰ.1.exercises 2.on weekends 3.ever 4.how often 5.hardly ever 6.go to the moviesⅱ.always(100%) usually often sometimes hardly ever never(0%)ⅲ.1.a 2.c 3.b 4.a 5.cⅳ.1.usually 2.never 3.hardly 4.often 5.oftenⅴ.on weekends,mike always goes to movies.peter usually watches tⅴ.jenny often reads books.li lei sometimes goes to the park.tom hardly ever plays soccer.bill never goes shopping.阅读理解： 1、bacbb    2、ccbab