以下是四种粒子的结构示意图，结合图示回答下列问题．

（1）属于同种元素的粒子是____；（填字母，下同）
（2）化学性质相似的粒子是____ 

阅读下面材料，在空白处填入适当的内容(1个单词)或括号内单词的正确形式。

      “Equal pay for equal work” is a phrase by the American women who feel they are ____ (fair) treated by society.They think it is not right for women to be paid less than men for the____ amount of work.Some people say men have ____  (many) duties than women.A married man has to earn money to support his family and make important ____ (decide)，so it is right for them to be paid more.Some are even against married women ____ (work) at all.When wives go out to work，they say，the home and children are given no attention ____ ．If women are encouraged by equal pay to take up jobs，they will be ____ (able) to do the things that they are best at doing：making a nice home and bringing ____ children.Women who disagree say that they want to escape from the limited place which society wishes them to fill and have ____ freedom to choose between a job and home life，____ a mixture of the two.In fact women have the right not only to equal pay but also to equal chances.

已知点$F\left(\sqrt{2},0\right)$，$A\left(-1,0\right),B\left(1,0\right)$，直线$x=\frac{\sqrt{2}}{2}$上有两个动点$M,N$，始终使$\angle MFN=45°$，三角形$MFN$的外心轨迹为曲线$C,P$为曲线$C$在一象限内的动点，设$\angle PAB=\alpha$，$\angle PBA=\beta$，$\angle APB=\gamma$，则（    ）

根据广州有关规定，到2020年，全市常住人口应控制在1500万以内，应该说，这“1500万”是让广州人活得“舒服”的指标。下列说法正确的是（）