写出近义词

激烈—____    挑战—____    超过—____

欲测定某石灰石样品中碳酸钙的质量分数（碳酸钙在高温下分解生成氧化钙和二氧化碳；石灰石样品中的杂质受热不分解，且不与酸反应），甲、乙两位同学分别设计了如下两个实验方案：

方案一：①称取石灰石样品质量8g；②用酒精灯加热样品，直至质量不再改变；③将固体残余物放在干燥的器皿中冷却后称得质量6.9 g；④计算。

方案二：①称取石灰石样品质量8 g；②加入质量分数为7.3%的盐酸100 g，使碳酸钙完全反应；③向反应后的溶液中加入含溶质3.2 g的氢氧化钠溶液，恰好中和多余的盐酸；④计算。

请回答下列有关问题：

（1） 碳酸钙在高温下分解的化学方程式是____ ；
（2） 你认为上述方案中，切实可行的是方案____ ，不选用另一方案的原因是____ ；
（3） 求方案二样品中碳酸钙的质量分数____ 。

如图所示，木块放在水平面上，用弹簧测力计沿水平方向拉木块使其做直线运动，两次拉动木块得到的s﹣t图象分别是图乙中的图线①②，两次对应的弹簧测力计示数分别为F₁、F₂，两次拉力的功率分别为P₁、P₂，则F₁____F₂，P₁____P₂（均选填“＜”、“=”、或“＞”）

    Most people in America like having the surprise party. It's very popular. They think it is very exciting to have surprise parties for their friends or family members. They often plan a surprise party for special events like someone's birthday. If you want to know what a surprise party is like, please look at the following example.

    One Saturday night, Sam's wife asked him to go to the kitchen and bring her a glass of water. Sam walked to the kitchen. When he opened the door, he saw a “bear（熊）” standing in front of him! Sam was very scared and wanted to run away at once. Just then the “bear” took off his costume(服装).

    It was Sam's friend John! When he turned back, he saw some other people standing behind him. All of them said “Surprise! Happy birthday!” to him.

    In fact, we can have many kinds of surprise parties. A successful surprise party always makes people feel surprised and excited. Would you like to plan a party like this for your friends or family members?