如图，一架长2.5米的梯子AB斜靠在竖直的墙AC上，这时B到墙AC的距离为0.7米．

（1）若梯子的顶端A沿墙AC下滑0.9米至A₁处，求点B向外移动的距离BB₁的长；
（2）若梯子从顶端A处沿墙AC下滑的距离是点B向外移动的距离的一半，试求梯子沿墙AC下滑的距离是多少米？

根据文章及首字母提示，填入恰当的单词完成短文

    It was Mr Hill's birthday yesterday. He was one h____ years old and many people came to his birthday party.

      A reporter came to the party and a____ him a few questions.

“Many people want to know h____ to live a long life," the reporter said. "Could you tell us a____ it?" "That is — I a____ get up at six in the morning," said Mr Hill," and have three meals a day. Never drink."

   “B____ my uncle also did so," said the reporter, said he o____ lived to be eighty. W____ do you think of that?

    “He didn't k____ it long enough,” was the old man's a____ ．

作文：

       请以“重拾好心情”为题写一篇作文。

       温馨提示：①选择你最擅长的文体；②文中不要出现真实的姓名和校名（可用化名代替）；③文章不得少于600字（若写诗歌，不少于20行）；④请不要抄袭。

下列实验操作中，能达到实验目的的是：