下列不属于细胞壁增长方式的是（）A、环纹导管 B、螺纹导管 C、网纹导管 D、矩形导

     Sam had a dog. Its name was Tod. It was very helpful, but it ate too much. So he didn't like it, he wanted
to    1   it. He    2   Tod and put it in a small boat. He rowed the boat to the   3    of a big river. Just as he   4   
the poor animal into the river, the boat began to go down.    5   the man and Tod    6   into the river.
     Tod was able to swim,    7   Sam couldn't. The dog bit the rope (绳子) and broke (破坏) it. It tried its best
to swim to   8    Sam. The man was saved, so he was very thankful for the dog and he didn't want to kill the
dog    9  . From then on, he gave the dog as    10   as it wanted.