如图，A、B为两容器，用一带阀门的管子相连，装有同一种液体，液面相平，则a、b两处的压强p_a ____p_b（填“＞”、“＜”或“=”）．当打开阀门时，液体 ____（填“流动”或“不流动”）．

​

阅读理解

    Hello, I'm Li Lei. My weekend is very busy. I usually get up at 6:30 in the morning. I eat breakfast at 7 o'clock. Then I do morning exercises at 8 o'clock. I often do my homework on Saturday morning. I play sports in the afternoon. I usually clean my room on Sunday morning. In the afternoon I often read books and watch TV. This is my weekend.

本文的说明顺序是____，它的结构形式是____。

氯元素有多种盐类，其中亚氯酸钠（NaClO₂）亚氯酸钠受热易分解．以氯酸钠等为原料制备亚氯酸钠的工艺流程如下：

请回答下列问题：