如图是20世纪初西方报刊上的一幅时局漫画《慈禧太后跑路》，关于这一时局的正确说法是（  ）

已知$\overrightarrow{a}$,$\overrightarrow{b}$是平面向量，若$\overrightarrow{a}$$\perp$($\overrightarrow{a}$-2$\overrightarrow{b}$)，$\overrightarrow{b}$$\perp$($\overrightarrow{b}$-2$\overrightarrow{a}$)，则$\overrightarrow{a}$与$\overrightarrow{b}$的夹角是（  ）

海带中含有大量的碘，但活的海带仍然能够继续吸收海水中的碘元素，这一现象主要与海带细胞中的哪个结构有关？（   ）

    On a cold winter evening, I was walking home, tired and hungry, when suddenly came screams(呼喊声) from behind some tress.1， I slowed down to listen, and 2 that what I was hearing were the sounds of a fight. A woman was being3not far from where I stood.

    “Should I go to help her？” I thought. I was worried about my own 4，and I regretted having suddenly decided to take a new way home that night.“What if I am5too? Shouldn't I just6to the nearest phone and call the police？” But already the girl's7were growing weaker. I knew it was time for me to act fast because I could not8the life of this unknown woman，9 it meant risking my own life.

    I am not a 10 man. I didn't know where I found the11and physical strength(体力), but once I had finally12to help the girl, I became suddenly changed. I ran behind the bushes and 13the attacker off the woman. Struggling, we fell to the ground, where we fought for a few minutes 14the man jumped up and ran away.

    15 heavily，I stood up and came up to the girl, who was crying behind a tree. In the 16，I could not see her clearly, but I could certainly17her shock. Not wanting to frighten her any further, at first I spoke to her from a distance.

    “It's OK，” I said 18.“The man ran away. You're safe now.”There was a long stop and then I heard the words, said in both wonder and 19“Dad, is that you？” And then, from behind the tree, stepped my youngest 20， Katherine.

从装有若干个大小相同的红球、白球和黄球的袋中随机摸出1个球，摸到红球、白球和黄球的概率分别为 $\frac{1}{2}$ ， $\frac{1}{3}$ ， $\frac{1}{6}$ ，从袋中随机摸出一个球，记下颜色后放回，连续摸3次，则记下的颜色中有红有白但没有黄的概率为（   ）