Yesterday was Father's Day. Many things happening between my father and me crowded my mind. But one thing made a deep impression on me.

    It was a Sunday morning, and I was in a 1 mood (情绪). Two of my friends had gone to the movies the night before and hadn't invited me.I was in my room2ways to make them sorry when my father came in. “ Want to go for a ride today,Berk? It's a beautiful day.”

    “No! Leave me alone!”Those were the 3words I said to him that morning.

    My friends called and 4 me to go to the mall with them a few hours later. I forgot to be5with them and then went with them.When I came home，I found a6 on the table.My mother put it where I would be sure to see it. “ Dad has had an 7 Please meet us at Highland Park Hospital.”

    When I reached the hospital ,my mother came out and told me a car hit my father and his injuries were extensive(大曲积的). “Your father told the driver to leave8 alone and just call 911, thank God! If he had moved Daddy, ….”

    My mother may have said more，but I didn't hear. I didn't hear anything 9 those terrible words： Leave me alone. My dad said them in order to10 himself. He didn't want to be hurt more. How much had I hurt him 11 I shouted out those words at him earlier in the day?

    It was several days later that he was12 able to have a talk.I held his hand gently, afraid of hurting him.

    “ Daddy... I am so sorry...''

    “It's okay, sweetheart. I'll be okay.”

     “No,” I said, “I mean about13 I said to you that day.You know, that morning?"

    He looked at me and said, “Sweetheart, I remember14 about that day, not before, during or after the accident. I remember telling you goodnight the night before，though." He managed a weak smile.

    My English teacher once told me that words have great power. They can hurt or they can heal(治愈）.And we all have the power to 15 our words.I am going to do that very carefully from now on.

    I've loved my mother's desk since I was just tall enough to see above the top of it as Mother sat doing letters. Standing by her chair, looking at the ink bottle, pens, and white paper, I decided that the act of writing must be the most wonderful thing in the world.

    Years later, during her final illness, Mother kept different things for my sister and brother. “But the desk,” she said again, “is for Elizabeth.”

    I never saw her angry, never saw her cry, I knew she loved me; she showed it in action. But as a young girl, I wanted heart-to-heart talks between mother and daughter. It never happened. And a gulf opened between us. I was “too emotional”. But she lived “on the surface”. As years passed and I had my own family, I loved my mother and thanked her for our happy family. I wrote to her in careful words and asked her to let me know in any way if she chose that she did forgive me. I posted the letter and waited for her answer. None came. My hope turned to disappointment, then little interest and, finally, peace—it seemed that nothing happened. I couldn't be sure the letter had even got to Mother. I only knew that I had written it, and I could stop trying to make her into someone she was not.

    Now the present of her desk told me, as she'd never been able to, that she was pleased that writing was my chosen work. I cleaned the desk carefully and found some papers inside—a photo of my father and a one-page letter folded and refolded many times. She had given me an answer in a way she chose. Mother, you always chose the act that speaks louder than words.

为了研究人的T细胞对B细胞的影响，研究人员将来自于同一个体的B细胞等分为三组，每组培养液中加人的细胞种类如表所示（“+”表示加入该细胞，“﹣”表示未加人该细胞）．将三组细胞在相同条件下培养．实验结果如图所示．

下列分析不正确的是（　　）