双生子分析的基本原理是通过比较同卵双生子和（或）异卵双生子人群中某疾病和症状发生率的

若一个多边形除了一个内角外，其余各内角之和为2570°， 则这个内角的度数为   [ ]

A.90°    

B.105°    

C.130°    

D.120°

阅读下面短文，根据短文内容及所给中文提示，写出空白处各单词的正确形式。每空限填一词。(10分)

Lucy is a good student. she is very busy this    (学期). She will    （面临）the coming _______(考试). They are very important. because she doesn't want to      （失去）the chance to get to the high school. Last week, she   （做梦，梦到）that she was swimming in a sea of paper. Her mother said she was too stressed out and she should pay more ______(注意)to sports and try to eat healthy food to get enough energy. She used to eat _____（糖果）.This week she eats more fruit and vegetables instead of    （甜的）food. Also, she runs in the playground after school every day. Now she feels ___(不同地).She feels much better than before. She doesn't____ (担心)about her study at all.

男性，38岁。右耳听力下降1年。CT示右侧小脑脑桥角区类圆形占位病变，增强扫描病灶呈均一强化，右侧内听道扩大。诊断考虑为（）。

A.听神经鞘瘤

B.三叉神经鞘瘤

C.脑膜瘤

D.胶质瘤

E.表皮样囊肿

某个系统在开发时，用户已经定义了软件的一组一般性目标，但不能标识出详细的输入、处理及输出需求；开发者也可能暂时不能确定算法的有效性、操作系统的适应性或人机交互的形式。在这种情况下，采用（）开发最恰当。

A.瀑布模型

B.迭代模型

C.原型模型

D.螺旋模型

室上速的临床特征是（）

A.发作时心率多超过200次／分

B.突然发作，突然终止

C.第一心音强度一致

D.发作时心律规则且固定

E.常伴发热