A：自然灾害是发生在地球表层系统中，能造成人们生命和财产损失的自然事件
B：人类活动在一定程度上可以改变自然灾害发生的频率、影响范围和危害程度
C：自然灾害不仅造成直接经济损失和人员伤亡，而且还会带来各种间接损失
D：自然灾害不会影响社会稳定和持续发展
It's Sunday today. Sam and his friends are washing(洗)a car for Mr. Green. They can give the money from the car washing to their school football team. Mary and her friends are seeing a funny movie. They see an interesting cat in the movie. Ann is in the park with her mother. They're talking under a big tree. I think they are having a good time. Joan wants to know what her friend is doing. Her friend is in Japan, so Joan is writing a letter to her friend on her computer. May is cleaning the house with her parents. The family are very busy, but they're very happy. They are working and singing.
在供需平衡的某商品市场上，假设政府基于某种目标，决定对该商品实施价格上限制政策，其他条件不变。图Ⅰ（P⒈表示政策实施前价格，P⒉表示政策实施后价格）中能反映该政策实施后价格变动的是( )
关于美国的叙述，正确的是（ ）
