题目

请用适当的词完成下面的短文。每个空只能填写一个形式正确、意义相符的单词。 Hello！My name is Gina Green. This is my . It's a red schoolbag. I can schoolbag.S－C－H－O－O－L－B－A－G, schoolbag. My ruler, dictionary and watch are it. My ruler is red. My dictionary is English dictionary. It is blue and red. What is the watch？It is yellow.Is nice？An ID card is in schoolbag, too. It isn't my ID card. Mine is in the morning.I can't find it now. It's Bill Brown's. His is on it. I will(将会) him. His telephone number is 256－7986.（本题满分13分）在平面直角坐标系上,设不等式组所表示的平面区域为，记内的整点(即横坐标和纵坐标均为整数的点)的个数为（1）求；并求数列的通项公式；（2）数列的和前项为，求数列的前n项和；（3）设，数列的和前项为，求证：