如图，△ABC的两条角平分线BD、CE交于O，且∠A=60°，则下列结论中不正确的是（   ）

下列工具哪些是唐朝时创制的（  ）

①耧车 ②水排 ③曲辕犁 ④筒车 ⑤翻车

根据短文内容，选择正确答案。
Hello, friends!
    My name is Zhou Dan. I'm a Chinese girl. I'm twelve. I'm from Zhengzhou, China. Do you know Zhengzhou? It's in the middle of China. I'm in No. 8 Middle School. There are about 900 students and 50 teachers in our school. It is a good school in Zhengzhou: I'm in Class 2 Grade 7. There are 49 students in our class: 29 girls and 20 boys. My English teacher is Miss Zhao Dan. Our names are almost the same, right? She is nice to me. We're good friends. I like English, and I like music, too. I want to find a pen-friend. Please write to me.
                                                              Yours,
                                                            Zhou Dan

在一定条件下，RO₃^n－和氟气可发生如下反应：RO₃^n－＋F₂＋2OH^－＝RO₄^－＋2F^－＋H₂O。从而可知在RO₃^n－中，元素R的化合价是

如图，下列图案是我国几家银行的标志，其中轴对称图形有（   ）