白色点滴板（见下图）是带有孔穴的白色瓷板，可用于显色、生成气体或沉淀的微型化学反应。下列各组物质中不合适在白色点滴板中进行实验的是（）

正方形ABCD中，点O是对角线DB的中点，点P是DB所在直线上的一个动点，PE⊥BC于E，PF⊥DC于F．

（1）当点P与点O重合时（如图①），猜测AP与EF的数量及位置关系，并证明你的结论；

（2）当点P在线段DB上（不与点D、O、B重合）时（如图②），探究（1）中的结论是否成立？若成立，写出证明过程；若不成立，请说明理由；

（3）当点P在DB的长延长线上时，请将图③补充完整，并判断（1）中的结论是否成立？若成立，直接写出结论；若不成立，请写出相应的结论．

       ①输入 , 输出它的相反数             

       ②求面积为 的正方形的周长

       ③在三个不等实数 中，求最大数

       ④求函数 的函数值

其中不需要用条件语句来描述其算法的有             （    ）

阅读理解

    It may be hard to believe, but the American Revolution(革命)—the war that freed the American states from British control—began over a cup of tea. Tea was not the only thing that caused the war, of course, but it played a very big part.

    The British people's love of tea is well-known. When the British won control over mush of North America in the early 1700s, they brought their tea- drinking habits with them. Tea quickly became the continents most popular drink. As tea could not be grown locally, just as in Britain, it was shipped into the country—mostly from India.

In the early 1700s, the Britain government made a special deal with the East India Company, as an English trading company. They agreed that no other company was allowed to bring tea to Britain or any country controlled by Britain, including America. It was a great deal for the East India Company, since it meant that the company could decide whatever price it wanted for its products. And it always decided on a high price!

In North America, the local people did not like having to pay such high prices. Instead of overpaying for tea from the British, they turned to Dutch traders, who secretly brought tea to the country that was just as good—and much less expensive. Although this broke the law, the American people didn't care. They got the same cup of tea at a much lower price.

The East India Company, however, didn't like this at all. By the 1760s, they were losing millions of pounds each year to Dutch traders—a huge amount of money in a time when ￡60 a year was considered a good income. Instead of reducing their prices to compete with the Dutch, the company asked the British government for help and the government agreed.

    In 1767, the British introduced new law that increased the prices of all goods which were brought into America. These laws helped make the East India Company even richer and forced local people to pay much more for everything. The American leaders asked the British government not to do so, but the British refused to listen. These unfair laws increased Americans' anger about British rule and the rest, as they say, is history.