Most Chinese eat three meals a day. In the past,they had breakfast in the morning, a big lunch at noon, and a light supper at night.

    But now both men and women in the big cities have to work on the weekdays. So they often eat bread, eggs, milk and porridge forbreakfast at home. For lunch, Chinese take-away food is very popular. They often have a quick lunch in their workplaces.

    After work in the afternoon, they have more time for supper. They usually eat a big meal at home. Wives often cook meat, fish, chicken, vegetables and rice for their family.You can also find dumplings and noodles on the table in most families of northern(北方的)China.

三个体积相同而材料不同的球A、B、C，分别静止在不同深度的水里，以下说法正确的是（　　）

外出旅游最常用的地图有(     )
①导游图  ②地形图    ③政治地图    ④交通图

下列区域中，光照充足但热量不足，土地生产力较低的是（   ）