阅读下面这首宋词，然后回答问题。

昭君怨·咏荷上雨      

杨万里

午梦扁舟花底，香满两湖烟水。急雨打篷声，梦初惊。

却是池荷跳雨，散了真珠还聚。聚作水银窝，泛清波。

    Kate's father took her to the hospital to see her one-day-old baby brother. They drove there straight from school. Kate had never been inside a hospital before.  ①This was a new experience for her.

    At the gate there was a large sign listing all the departments of the hospital, with arrows (箭头) showing how to find them. When Kate saw the A&E department(急救室), she asked,“What do those letters stand for?”“Accident and emergency,” replied her father,

②“Last spring, I took our sister there because she fell off her bike,”

在光电效应实验中，飞飞同学用同一光电管在不同实验条件下得到了三条光电流与电压之间的关系曲线（甲光、乙光、丙光），如图所示．则可判断出（　　）

我们每天看到太阳和星星东升西落，是因为(    )