I have a friend. He is with me every day. In the morning, I to school. He is behind me. He’s long. At , he’s beside me. He’s . In the evening, I come back home. He’s behind me too. He’s long again. I and he runs too. I jump, and he jumps too. But he can’t talk (说话) or sing. He is always quiet (安静的). He is my .

How do we know the time? We use clocks,     1     and phones to tell time. There is an     2     way to measure(测量) time. It’s a sundial. A sundial uses the     3     to tell time. The sun throws a     4     on the sundial. In the morning, the shadow is     5    . At noon, the shadow is     6    . In the afternoon, the shadow is long     7    . We can’t use a sundial at     8     because there’s no sun.