2013年是北京大学的115周年诞辰，这所大学的前身是（    ）

请在图中画出近视眼看物体所成像的大致位置，并在像上标出与物体上A点相对应的像点 。

801－347=____           583＋21=____

    I have a twin sister, Jenny. She has ____（长的）hair than me. Many people think ____（我们）must have a lot of things in ____（普通的，常见的）. That's not true. Jenny is creative. She won the best ____（奖项）in the school talent show. She likes making friends, so she is more ____（外向的）. But I like staying at home. And I watch TV ____（两次）a week because I have to go to school every day. I always get better ____（分数）but she is much less hard—working. So maybe I should help her. ____（然而）, we also have some similarities. We ____（都）like sports and going shopping, so we can talk about and ____（分享）everything. I love my sister.

下列关于人类遗传病的叙述，错误的是（   ）