＿＿＿for us to surf on the sea in summer!

A．What exciting is it

B．How exciting is it

C．What exciting it is

D．How exciting it is

具有高含水量、高孔隙性、低渗透性、高压缩性、低抗剪强度、较显著的触变性和蠕变性等特性的土质类型是（）。

A．红黏土

B．膨胀土

C．湿陷性黄土

D．淤泥及淤泥质土