阅读下列材料，回答问题。
材料一：我国某地理科考队对非洲大陆地形、气候、热带草原区的农牧业生产和环境等方面进行了科学考察
材料二：非洲沿赤道地形剖面图和东非裂谷带图
1929—1933年经济大衰退中受害最深的是（ ）
In America, there are chores(杂活) for children of different ages. American people think that it's important to tell children their duty in the family.
Ages 4-6
Ages 6-12
Ages 13 and Up
-Make their bed;
-Clear dishes from the table;
-Set the table;
-Get the mail from the mailbox;
-Take care of pets;
-Cook simple food;
-Help wash the car;
-Vacuum(吸尘) and sweep;
-Take out the rubbish.
-Wash windows;
-Clean out fridge;
-Prepare a meal;
-Make shopping lists;
-Mow the lawn(剪草坪)
