【单选题】已知挡土墙高4.5m,墙背直立、光滑,墙后填土为砂土并与墙顶齐平,c=0,φ=30°,γ=18kN/m 3 ,γ′=9kN/m 3 ,地下水位位于墙顶,则距墙顶深度4m处的主动土压力强度为()。
【简答题】The holiday was a(n) ____________ (forget) experience.A. unforgettable
【单选题】Stephen Bona was on holiday when he saw a huge and gray shark leap out of the water at the sea.
【简答题】The holiday was a(n)___(forget)experience.