要使一杯pH=7的NaCl溶液变成pH=9，下列方法可行的是
A．加入蒸馏水
B．加入稀盐酸
C．加入NaCl固体
D．加入NaOH溶液
答案：D
题目分析：要使一杯pH=7的NaCl溶液变成pH=9，即要使溶液由中性变为碱性，应该加入碱溶液或碱性溶液，A、蒸馏水呈中性，错误，B、稀盐酸呈酸性，错误，C、NaCl固体溶于水呈中性，错误，D、NaOH溶液呈碱性，PH＞7，正确，故选D
北京每月22日定为“让座日”，在公交车上经常让座的乘客，将有机会获得奖励。对此，网民看法不一。请根据下表所提供的信息，写一篇100字左右的短文，谈谈你自己的看法。
Beijing named the 22nd of every month as “Seat-giving Day” to encourage passengers on public transport to give up seats to those in greater need, and those commuters who refuse to do so will get criticized. This activity arouses different opinions among netizens. |