【数据分析】若撤去图乙中的C装置，则测得工业烧碱的纯度将____（填“偏高”、“偏低”或“无影响”）。

有“生命中枢”之称的部位是

下列地区被称“北半球的寒极”的是（    ）

（2015•威海）已知：抛物线l₁：y=﹣x²+bx+3交x轴于点A，B，（点A在点B的左侧），交y轴于点C，其对称轴为x=1，抛物线l₂经过点A，与x轴的另一个交点为E（5，0），交y轴于点D（0，﹣$\frac{5}{2}$）．

根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    My name is Bill. I am a student in No. 10 Middle School. I am very busy this 1. On June 3rd, we 2 a school trip. I need to buy some food 3 the trip. On June 6th, we have a P.E. test. I am a fat boy, so it is really 4 for me. June 15th is my twelfth 5. I ask my friends to 6 to my party. I need to buy some things for my party in the 7. June 26th is my friend Alan's birthday. I know 8 like(s) ping-pong. I want to buy a ping-pong bat for him. On the last day of June, June 9, my school has a book sale in the school library. I can buy some books at good 10. I hope (希望) I can have a good time this month.