Davidwantedtobuyabicycle，butitwasnotsoeasy．Heplannedtobuyagoodone，（61）___itwouldbeexpensive．Afterlookingatdifferenttypesofbicyclesinmanybikeshops，he（62）___（decide）tobuyamountainbike．However

　　David wanted to buy a bicycle，but it was not so easy．He planned to buy a good one，

　　（61）___it would be expensive．After looking at different types of bicycles in many bike shops，he （62）___ （decide） to buy a mountain bike．However，that was not all．He also had to get many accessories（配件） for it．Since he couldn't afford （63）___ （buy） them all at once，he bought a helmet and gloves first，and then，tools，bags to hang on the bike and special bike shoes and light．After that，he found that all these were （64）___ （actual） more expensive than the bike．

　　With this bike，he started to train himself to be a bike racer，（65）___ might take a lot of time and energy．This was going to be a very difficult process and could be very （66）___ （tire） at first．However，in order to be （67）___good racer，it was necessary．He had to ride 200-300miles each week．In addition，he had to be very （68）___ （care） with what he ate and drank．Whenever he ate or drank something unhealthy，such （69）___ candy or coffee，he was slowed down and his training was disrupted（中断）．（70）___ was even more challenging for David was that he also had to work full-time to support himself．