根据首字母提示或汉语意思填空，使短文意思通顺，结构完整。
   When I was young, I studied hard all the time. But ____ u_________,my grades were low and I nearly lost ____ (信心) _________in myself .
  My father was worried about it .He took me to the garden .Pointing to two rows of trees ,he asked me ,"Do you know what trees they are ?" I watched ____ c_________ and answered, "They are poplars and gingkoes. " My father asked me to ____ c_________ poplars with gingkoes and find out the____ (不同) _________ between them .It’s very clear that poplars are much____ t_________ than the gingkoes.
   My father told me the two rows of trees ____ （种）_________ at the same time . While being planted , they were as tall as each other .With the same sunlight ,the same water and the same care, but why are the poplars so tall and the gingkoes are so ____ s_________?
I stood there without ____ s_________ a word . Then my father said ,"Boy ,you know ,the valuable things often grow up slowly."
I knew what my father meant by saying so .From then on, I studied harder and harder .And my grades ____ i_________ greatly .Three years later ,I succeeded in entering Beijing University .