用量筒量取液体时，某同学操作如下：量筒放平稳，面对刻度，仰视液体凹液面最低处，读数为19mL。倾倒出一部分液体，又俯视液体凹液面最低处，读数为11mL。这位同学取出液体的体积是

在等腰三角形ABC中，∠A＝100°，则∠B＝____ 度。

在生长健壮的枝条上，剥去一圈树皮，露出木质部，过一段时间，出现了瘤状物，瘤状物的部位是在  (    )

已知线段AB=5cm，点C在直线AB上，且BC=3cm，则线段AC=____ ．

C

    It is a true story. Once upon a time, one of Alex's horses was stolen by his neighbor. Alex went to the neighbor's home with a policeman to get his horse back. But the neighbor refused to give the horse back. He said that it was his horse.

    Suddenly Alex had a good idea. He put both of his hands over the eyes of the horse and said to the neighbor, “If this is your horse, then you must tell us in which eye the horse is blind.”

    “In the left,” said the neighbor. Alex took his hand from the left eye of the horse and showed the policeman that the horse was not blind in the left eye.

    “Oh, I have made a mistake,” said the neighbor. “He is blind in the right eye.” Alex then showed that the horse was not blind in the right eye, either.

“I have made another mistake,” said the neighbor.

    “Yes,” said the policeman, “and you have also proved that the horse isn't yours. You must give it back to Mr. Alex. ”