One day，four lawyers were riding their horses along a country road. There had been a rain. Water was dripping (滴) from the trees，and the grass was wet. They rode slowly，talking and laughing. Suddenly they heard some noises from the tree above them. “What is the matter?” asked the first lawyer. “Oh, it's only some old birds!” said the second lawyer. “The storm made one of the babies fall out of the nest. It is too young to fly, and the mother bird is very worried.” “What a pity! It’ll die down there in the grass,” said the third lawyer. “It doesn't matter. It's only a bird,” said the second lawyer. Then they rode on, talking and laughing as before. But the fourth lawyer, whose name was Abraham Lincoln, stopped. He got down from his horse and took the little one in his big warm hands.
“Never mind, my little fellow ,” said Mr. Lincoln. “I will put you back in your little nest.” He climbed up the tree and put the bird softly into their warm little home. A few minutes later, Mr. Lincoln joined them again. His shoes were covered with mud and he was wet. Then the other three laughed at him. They thought it was foolish for a strong man to do so much just for a young bird. “Gentlemen,” said Mr. Lincoln, “I could not sleep tonight if I had left the helpless bird in the grass.” Later Abraham Lincoln became very famous as a lawyer. He also became the president of America. He was one of the greatest American presidents.
小题1:The reason why the mother bird was worried was that __________.
A．there was a rain
B．the lawyers were under its tree
C．one of its babies fell out of the nest
D．it could not fly小题2:The underlined phrase “little fellow” in paragraph 2 means __________.
A．the mother bird
B．Lincoln's little friends
C．the other three lawyers
D．the baby bird小题3:The other three lawyers laughed at Lincoln because __________.
A．he climbed the tree
B．he was wet
C．his shoes were covered with mud
D．they thought it foolish for him to do so小题4:From the passage we know Lincoln __________.
A．liked riding horses
B．was very kind and loved birds and animals
C．liked being laughed at
D．wanted to be the president of America then
和
水平放置，
间接有阻值为
的电阻，导轨相距
，空间有竖直向下的匀强磁场．质量为
，电阻为
的导体棒
垂直于导轨放置，并接触良好．用平行于
，经过时间
导体棒
．求
的大小． 
拉动导体棒
．求恒力
少的分泌