Today, many people in the world's largest cities already live in tiny apartments.

—Ken did badly in his math test. I'm terribly worried about the result.

—                      .

公共物品

-I'll also throw in the discount of 10% on your up front deposit. What do you think about this suggestion?

-______________  

党的二十大提出的“六个必须坚持”，是习近平新时代中国特色社会主义思想的世界观、方法论和贯穿其中的立场观点方法的重要体现。（ ）

刘某在商场购买一台液晶电视机，并附有产品合格证。刘某使用两个月后，电视机出现图像不清的现象。刘某去找商场要求更换，商场辩解称电视机并非其生产，要求刘某与电视机厂进行交涉。

请根据《产品质量法》回答以下两道单项选择题：

Maggie believes that it is easier to keep track of the money coming in than to keep track of the money going out.

IS曲线：（    ）

 每一条等成本曲线和等产量曲线的切点所形成的曲线是（       ）