题目

假设你是李华，你的朋友Peter知道你们学校最近举行了“给自己写一封信”活动，来信询问有关情况，请你根据以下内容写一封回信。1）活动的目的；2）带来的好处；3）给他的建议。注意：①词数100左右；②可适当增加细节，使行文连贯。Dear Tom, Yours,Li Hua 答案：Dear Tom, I have received your letter knowing you areinterested in our writing-to-myself activity. Now let me tell you somethingabout it. First, this activity was really interesting.We students wrote a letter to ourselves and wrote about our happiness, sorrowsand our future plans in it. In the letter we also analyzed our strengths andweaknesses. At the same time, we reflected our relationship wit附加题：如图1，菱形纸片ABCD中，AB=1，∠B=60°，将纸片翻折（如图2），使D点落在AD所在直线上，并可在直线AD上运动，折痕为EF．当12＜DE＜1时，设AB与DC相交于点G（如图）．（1）线段AD与DG相等吗？△ADG与△BCG的面积之和是否随着DE的变化而变化？为什么？（2）设AD=x，重叠部分（图3中阴影部分）的面积为y，求出y与x之间的函数关系式，并写出自变量x的取值范围以及面积y的取值范围．?