阅读理解

      There are many festivals (节日) in our school. This month is October. In October, there is a Sports Festival. We have a basketball game and a volleyball game during (在....之间) the festival. In the middle of this month, we have an English test during the English Festival. October the nineteenth is the day for a school trip; we go to Beijing with the teachers. On the last day of this month, there is a Music Festival. On that day we can enjoy beautiful songs, dances and piano music. It is really wonderful. Next month, there is an Art Festival. Students often display(展示) their pictures on that day.

在广东，一天之内，就有20多万男人剪去了长辫子。你认为这一现象会发生在(  )

在伏安法测电阻的实验中，待测电阻R_r的阻值约为200Ω，电压表V的内阻约为2kΩ，电流表A的内阻约为10Ω，测量电路中电流表的连接方式如图（a）所示，结果由公式R_x= $\frac{U}{I}$ 计算得出，式中U与I分别为电压表和电流表的示数，若将图（a）和图（b）中电路测得的电阻值分别记为Rx₁和 $R_{x_2}$ ，则____（选填“ $R_{x_1}$ ”或“ $R_{x_2}$ ”）更接近待测电阻的真实值，且测量值____（选填“大于”“等于”或“小于”）真实值．

用石墨作电极，电解1 mol/L下列物质的溶液，溶液的pH保持不变的是（      ）

如图所示，一汽车装备了具有“全力自动刹车”功能的城市安全系统，系统以50Hz的频率监视前方的交通状况．当车速v≤10m/s、且与前方静止的障碍物之间的距离接近安全距离时，如果司机未采取制动措施，系统就会立即启动“全力自动刹车”，使汽车避免与障碍物相撞．在上述条件下，若该车在不同路况下的“全力自动刹车”的加速度取4～6m/s²之间的某一值，则“全力自动刹车”的最长时间为（   ）