根據液體壓強的特點及攔河壩的功能可知，攔河壩橫截面的形狀是圖中的____________________(是甲？乙？丙？還是丁？）

熱心網友

梯形，下寬上窄。沒圖，只好大概說一下形狀了 ：）

熱心網友

梯形，上窄下款

熱心網友

失敗，沒有圖我怎么答呀！不過是上寬下窄。

熱心網友

沒錯，就是梯形，從水面到水下逐漸變寬，是為了適應逐漸增大的水壓，保證大壩的安全和穩定性。

熱心網友

上圖正確

熱心網友

應該是：`````_______``````````````````````````````````````_______````````````/```````\`````````````````水`````````````````/```````\```````````/``````````\```````````````水```````````````/``````````\``````````/`````````````\`````````````水`````````````/`````````````\`````````/````````````````\```````````水```````````/````````````````\````````/```````````````````\`````````水`````````/```````````````````\```````/``````````````````````\```````水```````/``````````````````````\``````/`````````````````````````\`````水`````/`````````````````````````\。