Geoffrey Hampden has a large circle of friends and is very popular at parties. Everybody admires him for his fine sense of humour-everybody, that is, except his six-year-old daughter, Jenny.

    Recently, one of Geoffrey's closest friends asked him to make a speech at a wedding reception. This is the sort of thing that Geoffrey loves. He prepared the speech carefully and went to the party with Jenny. He had included a large number of funny stories in the speech and, of course, it was a great success. As soon as he had finished, Jenny told him she wanted to go home. Geoffrey was a little disappointed by this but he did as his daughter asked.

    On the way home, Geoffrey wondered what Jenny thought of his speech.

注意：

1）所续写短文的词数应为50左右；

2）至少使用3个短文中标有下划线的关键词语；

3）续写部分只有一段，开头语已为你写好；

4）续写完成后，请用下划线标出你所使用的关键词语。

已知点P到圆的最大距离为11，最小距离为7，则此圆的半径为多少？

①有芒×有芒→有芒               ②有芒×有芒→有芒215+无芒70

③有芒×无芒→有芒               ④有芒×无芒→有芒101+无芒97．