cau 1 : rewrite the following sentences 1 she does not work hard , so she does not get good marks >> if .......................................................... 2 i am so busy , so i do not write to my friends regularly >> if i .............................................................................. 3 i do not know his address , so i can write to him >> if i .............................................................................. 4 the last time she went out him was 9 months ago >> it is ............................................................................... 5 mr. jackson is old , but he runs ten miles before breakfast >> although .................................................................. 6 we can not go to a trip because we are very busy >> if we ............................................................. 7 mekong is the longest river in indochina >> no river ............................................................ 8 hue is not as big as hcm city >> hcm city .................................................................. 9 please stop complaining about the heat now >> i wish you ................................................................ 10 the children enjoy eating ice-cream >> the children are .......................................................... 11 i am quite tall but you are taller >> i am not ................................................... 12 remember to check your luggage >> do not .................................................. 13 he is handsome but she does not trust him >> even though ......................................