下图表示细胞某些结构的组成成分，其中图中字母是元素符号，甲、乙、丙表示物质。下列有关叙述错误的是：

根据短文理解，选择正确答案。
Captain Goodfellow
    Do your children enjoy interesting stories, funny games, and exciting dances? Captain Goodfellow will be ready to teach all these things to children of all ages at the City Theatre on Saturday morning at 10:00, FREE.
Walking Tour of the Town
    Forget your worries on Saturday morning. Take a beautiful walk and learn about local history. Meet at the front entrance of the City Hall at 9:30. Wear comfortable shoes!
Film at the Museum
    Two European films will be shown on Saturday afternoon at the Museum Theatre. See Broken Window at 1:30. The Workers will be at 3:45. For further information, call 4987898.
International Picnic
    Are you tired of eating the same food every day? Come to the Central Park on Saturday and enjoy food from all over the world. Delicious and not expensive. Noon to 5:00 pm.
Do You Want to Hear “The Zoo”
     “The Zoo”，a popular rock group from Australia, will give their first US concert tomorrow night at 8 at Rose Hall, City College.

计算

15×15=225	34×36=1224
25×25=625	33×37=1221
35×35=1225	32×38=1216
45×45=2025	31×39=1209

85×85=____

如图，△OAC和△BAD都是等腰直角三角形，∠ACO=∠ADB=90°，反比例函数y= $\frac{6}{x}$ 在第一象限的图象经过点B，则△OAC与△BAD的面积之差S_△OAC﹣S_△BAD为（   ）

下列运算正确的是（   ）