题目

右图所示遗传系谱中有甲（基因设为D、d）、乙（基因设为E、e）两种遗传病，其中一种为红绿色盲症。下列有关叙述中正确的是 A．甲病基因位于常染色体上，乙病基因位于X染色体上 B．Ⅱ6的基因型为DdXEXe，Ⅱ7的基因型为DDXeY或者DdXeY C．Ⅲ13所含有的色盲基因来自Ⅰ2和Ⅰ3 D．Ⅱ7和Ⅱ8生育一个两病兼患的男孩的几率为1/8Today is Sunday. The children are playing in the park.Look!Who is the girl under the tree? She is Gina. What is she doing? Oh,she is reading.Look at the boys. Some are singing,and some are playing basketball. Oh,that is Peter. What is he doing now? He is playing chess (下棋) with his grandfather.They are very happy.(   ) 1. What day is it today?   A. Monday. B. Saturday.   C. Sunday. D. Weekend.(   ) 2. How many children are there?   A. Two. B. Three.   C. Four. D. We don't know.(   ) 3. Who is reading?   A. Gina. B. Peter.   C. Grandfather. D. Mike.(   ) 4. What are the boys doing?   A. Singing.   B. Playing basketball.   C. Playing football.   D. A and   B.(   ) 5. Are the children happy today?   A. Yes,they do.   B. No,they don't.   C. Yes,they are.   D. No,they aren't.