A：黄金作为商品，具有保值增值的功能
B：黄金作为商品，始终处于供不应求状态
C：黄金作为货币，其本质是一般等价物
D：黄金作为货币，可以当做社会财富被保存起来
Alice often _________ shopping with her mother at the weekend.
从洋葱的鳞片叶上撕取一小块材料制成的玻片标本，属于下列哪种类型（ ）
——Some students often drop litter carelessly in our school. What can we do?——We can _______ some signs to remind them not to do that again.
“高原绿了，农民富了”。说明黄土高原治理的根本是（ ）
