Ever since middle school,my sister Wang Wei and I have dreamed about taking a great bike trip.She persuaded me to buy a mountain bike after she bought one.After 1.          (graduate) from college,we 2.          (final) got the chance to take a bike trip.It was my sister 3.      

first had the idea to cycle along the entire Mekong River from where it begins to where it ends.

I am fond of my sister but she has one serious shortcoming.She doesn’t care 4.        details in her daily life.There were too many 5.          (difficult) for us to finish the trip.Our journey would begin at 6.      altitude of more than 5,000 meters.The air would be hard to 7.