A:土地改革时期
B:农业合作化时期
C:“大跃进”时期
D:“文化大革命”时期
图中两条曲线分别表示某地市区和郊区气压随海拔高度的变化,读图完成下列各题。
- There ________ many trees at the foot of the mountain.
- But now they are slowly disappearing because of human activities.