根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    My name is Linda. Amy is my best friend. She 1 long straight black hair and two big black eyes. 2 nose is very small. She is beautiful.

    She is 3, too. Amy likes animals, so she 4 helps her grandparents take care of (照顾) their cat and dog. She is also a 5 student in my class. She studies very hard 6 she often helps other students. After school, we often play together. We 7 swimming very much, so summer is our favorite season.

    She is not the only 8 in her family. She has a sister of only three years old. Her name is Lucy. Lucy is a cute girl. She 9 me sister the first time. When we go to the park, she wants to go to the 10, too. When we read at home, she wants to read, too. How funny!

下列细胞中寿命比较长的是（　）

下图是我国东南部某地等高线地形图，某校高中学生夏令营在图示区域进行了野外天文、地质、植被、聚落等综合考察活动。读图回答下列问题。

某生物的长尾对短尾为显性，控制基因为A﹣a，存在胚胎致死效应，假设有两种情况：甲情况为显性基因纯合致死；乙情况为隐性基因纯合致死．下列叙述不正确的是（　　）