Dear Daming，

    Thanks for your letter and the wonderful photos. I like them very much.

Here are some of my photos. I'm sending them to you . In the first photo，it is snowing. I'm making a snowman with my friends. In the second one，the sun is shining and the wind is blowing. I'm flying a kite in the park. In the third one，I'm swimming in the sea. In the last one，I am with my sister Lucy. We're playing chess.

Best wishes to you and your family.

Love，

Jack

根据书信内容选择正确答案。

东北地区农作物熟制是（    ）

卵原细胞在进行DNA复制时，细胞中不可能出现的是（    ）

再现历史，感受历史
***在《沁园春• 雪》中写到：“惜秦皇汉武，略输文才，唐宗宋祖，稍逊风骚。一代天骄，成吉思汗，只识弯弓射大雕。”这其中包含了哪几位历史人物？你最欣赏哪一位？谈谈你的看法？