—Jenny and Joe have________recently.

—How come？As far as I know，they have been good friends for many years.

如图，△ABC中，AB=3，AC=4，BC=5，D、E分别是AC、AB的中点，则以DE为直径的圆与BC的位置关系是（　　）

“吸进的是白色粉末，吐出来的是自己的生命。”这句话形象地说明了（）

I ____ （write）a letter to my friend yesterday.

注意：

1）文中不得出现你的真实姓名和学校名称；

2）语言通顺，意思连贯，条理清楚，书写规范；

3）词数 80 左右，邮件的开头和结尾已经给出，不计入总词数。

Dear John,

向你求助。请根据邮件内容写封回信。

Dear Li Hua,

    I will come to Nanjing in July and stay with a Chinese family for a week as an exchange student. To get along well with my host family, should I prepare any gifts? How can I help with the housework? What else should I do?

    Please write back soon.

Yours, John

Dear John,

    I'm glad you will come to China.

    I hope you will enjoy your stay in China.

Yours,

Li Hua