闪蒸罐的真空是靠（）产生的。A、水环式真空泵 B、蒸气喷射泵 C、顶部与气液分离罐相

       A little boy invited his mother to his school's first teacher-parent meeting. To the little boy's disappointment (失望), she said she would go. This    1    be the first time that his classmates and teacher    2    his mother and
he felt ashamed (丢脸) of what she looked.    3    she was a beautiful woman, there was a deep scar (伤痕)
that covered the whole right side of her face. The boy never wanted to    4     why or how she got the scar. 
      At the meeting, the people were impressed (留下印象) by the kindness and natural beauty of his mother in
spite of (尽管) the scar, but the little boy still felt uncomfortable and hid himself from everyone. However, he
could hear the conversation     5    his mother and his teacher. The teacher asked    6   , "How did you get the
scar on your face?" The mother replied, "   7    my son was a baby, he was in a room that caught fire. Everyone
was    8    afraid to go in because the fire was terrible, so I went in. As I was running toward his bed, I saw a
long     9    of wood coming down and I placed myself over him trying to keep him from hurt. I was knocked,
but luckily, a fireman came in and saved    10   of us." She said slowly, "This scar will be lasting, but to this day, I have never regretted (后悔) what I did." 
       At this point, the little boy came out running toward his mother with tears in his eyes. This was his first
time to hear the story. He    11   her in his arms and felt the great   12    from his mother. He held her hand
tightly for the rest of the day.