完形填空
When I was growing up, I didn't remember hearing the words “I love you” from my father. When your father1 says these words to you when you are a (n)2it gets tougher and tougher for him to say these words as he gets 3To tell the truth, I could not honestly remember 4 I had last said those words to him either. I decided to 5my ego (自尊心) aside and make the first move. After 6in our next phone conversation I blurted out (突然说出) the words, “Dad... I love you!”
There was a 7at the other end and he awkwardly (笨拙地) replied, “Well, same back to you!”
I smiled and said, “Dad, I know you 8 me, and when you are ready, I know you9 say what you want, to say.”
Fifteen minutes later my 10 called and nervously asked, “Paul11 is okay?” I explained to her perfectly.
A weeks later, Dad 12 our phone conversation with the words, “Paul, I love you.” I was at work during this13and the tears were rolling down my cheeks as I finally “14” the love. As I sat there in tears, I 15 that this special moment had taken our father-son 16 to a new level.
A short while after this 17 moment, my father narrowly18 death following heart operation. I have often thought 19 I did not take the first step and Dad did not 20 the operation, I would have never “heard” the love.
的电子以速度
沿AB边射入边长为a的等边三角形的匀强磁场区域中，如图所示，为使电子从BC边穿出磁场，磁感应强度B的取值范围为