图所示为《唐书》所载830名进士的出身分布比例，由此可见，唐代科举制

    One night, Mary heard some big1noise.  “Doh, Doh, …”It2 for a few minutes.  Mary went out of her bedroom to search everywhere.  Her parents were sleeping and there were no 3people in the house.  Mary 4 to her bedroom.
    Mary heard the noise again.  She thought, “Is it a cat?  Mike has a cat.  But cats miaow.  They don't make such noise.”
  “Maybe it's a bird5 around and looking for a place to rest.  No! That doesn't make any noise.”
    Maybe it's the whisper of my parents.  They 6 be7in their room.  But that noise wasn't a whisper at all.”
    Mary went to bed again but she heard the noise again. She was 8 and fell 9 her bed. Her legs were10  and she could not climb up any more.

在直角坐标系xOy中，曲线C₁的参数方程为$\left\{\begin{array}{c}x=\sqrt{7}\cos \alpha \\ y=2+\sqrt{7}\sin \alpha \end{array}\right.$（其中α为参数），曲线C₂：（x﹣1）²+y²=1，以坐标原点O为极点，x轴的正半轴为极轴建立极坐标系．

（Ⅰ）求曲线C₁的普通方程和曲线C₂的极坐标方程；

（Ⅱ）若射线θ=$\frac{\mathrm{\pi }}{6}$（ρ＞0）与曲线C₁，C₂分别交于A，B两点，求|AB|．

目前很多学校纷纷开展了对青少年的青春期健康教育活动。学校这样做将有助于中学生（    ）

①彻底消除青春期的烦恼                                                         ②提升保持身心健康的意识，增强正确处理青春期困惑的能力

③了解青春期生理发育的特点，悦纳青春期身体的变化             ④健康踏实地度过青春期