假定某病的患病率为10‰,用某项灵敏度为80%,特异度为90%的筛检试验检查1000人的人群,则误诊人数为()。
A.99
B.198
C.2
D.891
E.107
参考答案:A
句型转换。
1. My mother is short and heavy. (对划线部分提问)
____ ____ your mother ____?
2. My brother likes playing chess. (对划线部分提问)
____ ____ your brother____?
3. Ann is short. She has short straight hair. (合并为一句)
Ann is short ____ short straight hair.
4. Cathy is not tall or short. (改为同义句)
Cathy is of ____ ____.
5. I think Mary is cool. (改为否定句)
I ____ think Mary ____ cool.
在光纤纤维传中传播模式很多对信息传输是不利的,因为同一光信号采取很多模式传播,就会使这一光信号分为不同时间到达接收端的多个小信号,从而导致合成信号的畸变。