on the days?in the days?The days on which black people in the country could not travel without a pass are gone forever.You will make great progress in the days to come.两种用法都用?那有什么区别么?

on cold days与in the days区别 单项选择：The doctor asked him to stay _______ for two or three days.A.in bed B.on bed C.in the bed D.on the bed in the old days in the old days The doctor asked him to stay _____ for 2 or 3 days.A.on the bed B.in bed C.in the bed D.be in bed We shall never forget the days ( )we workedWe shall never forget the days ( )we worked together .A .that B .in which C .on which D .which on cold days与in the day区别 On hot days we often (b ) in the river.填空 However,the two countries in it on different days l am in beijing for five days.on the fi i'd like to spend ten days on the experiment i'd like to spend ten days on the experiment -----the next 10 days,I had a great time.A In B On C At D For 这道题怎么做 解释一下.The head master will return two days.A. on B. at C. to D. in .I’ll never forget the days ______ we spent together in the country.A.which B.on which C.when D.on that The po1ice ( )the drivers ( )drive more carThe po1ice ( )the drivers ( )drive more carefully on rainy days.A.encouraged/to B.warned/of C.urged/to D.advised/in in the old days the working people in our country____(look）down on 阅读理解China is becoming one of the most popular countries for a holiday.31.How long will the holiday last?A.Seven days.B.Five days.C.Nine days.D.Ten days.32.When will you arrive in Hangzhou?A.On Day 4.B.On Day 5.C.On Day 6.D.On Day 7.33.What wi