按要求写出分数．

如图3直线上有n个点，则图中有____条可用图中字母表示的射线，有____条线段；

某同学在做“用电压表和电流表测灯泡的电阻”实验时，连接电路如图所示．请指出他的接线中的错误，应如何纠正？

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根据氢原子能级图（如图）可判断（   ）

① How tall is it? ____     A. Zhang Yong.

② Who is the tallest boy? ____     B. Maybe 5 metres.

③ What size are your shoes?____     C. Forty yuan.

④ How much is your T-shirt? ____     D. Size 38

⑤ How old are you?____     E. I'm fifteen years old.