When Albert Einstein was young, he was a quiet child who spent much of his time alone. He was slow to talk and had difficulty in learning to read. When Albert was five years old, his father gave him a compass. Albert was filled with wonder when he discovered that the compass needle always pointed in the same direction ---- the north. He asked his father and his uncle what caused the needle to move. Their answers were difficult for Albert to understand. Yet he spent a lot of time thinking about them. He said later that he felt something must be hidden behind things. Albert didn't like school. The German schools of that time were not pleasant. Students couldn't ask questions. Albert said he felt as if he were in prison.. One day Albert told his uncle Jacob how much he hated school, especially mathematics. His uncle told him to solve mathematical problems by pretending to be a policeman. "You are looking for someone," he said, "but you don't know who he is. Call him X. Find him by using your mathematical tools." Albert learned to love mathematics. He was studying the _ mathematics of calculus while all his friends were still studying simple mathematics. Instead of playing with his friends he thought about things such as "What would happen if people could travel at the speed of his light?" Albert wanted to teach mathematics and physics. He graduated with honors, but it was a pity that he could not get a teaching job. We can learn from the passage that   _  .
Einstein became a mathematics teacher after graduation Einstein gradually loved mathematics with his uncle's help. Einstein's uncle was a policeman. Einstein liked playing with other children.