下列旅游景点,既具有较高美学价值,又具有较高历史文化价值的是( )
A:挪威峡湾
B:川西九寨沟
C:印度泰姬陵
D:杭州西湖
- Do you think the rain will stop tomorrow?
-__________. It has rained for ten days. It's too wet everywhere.
“玉兔号”周身金光闪闪,她的肩部有两片可以打开的太阳能电池帆板,好似“黄金甲”上的披风.结合材料回答下题.
已知等式 1n(n+1)=1n−1n+1 ,对任意正整数n都成立.计算: 11×2+12×3+13×4+⋯+1n(n+1) =____.