阅读下面材料，在空白处填入适当的内容（不多于3个单词）或括号内单词的正确形式。
I was nine years old when I learnt to ride a bike. The bike was a birthday present from my uncle. You can imagine how       (excite)I was when I saw the bike, and I begged my   uncle to teach me how      (ride) it right away.  However, before I got on the bike, I felt          (extreme) nervous and l was afraid that l would fall off and hurt     (me). My   uncle held onto the seat and helped me to get      the bike. While l was riding, he was running along beside me, holding the seat so I would not fall over .I was so   (grate) to him for his help. As I was practicing, I became more and more confident. Then, I heard my uncle
shouting, "You are riding it by yourself now!"I was both excited and scared. I was really riding by myself, but      if I fell off? Could I use the brakes to stop? As I was wondering about this, my uncle ran after me and got hold of the bike. I       (slow) down and came to a stop. My heart was still beating fast when I got off the bike.      (late)that day, having learnt how to get on the bike and get off it, I felt like l was walking on air! I am still thankful to my uncle for teaching me to ride a bike on my       (nine) birthday.