砂土可用作路基填料,但由于没有( ),受水流冲刷及风蚀易损坏,使用时可掺人黏性大的土。
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当管式渗沟长度为()时,其末端宜设横向泄水管分段排除地下水。
A. 100~200m
B. 100~300m
C. 200~300m
D. 300~500m
The author argues that the change to a nationwide banking systems should be ______.
A. gradual, so that regional banks have a chance to compete with larger banks
B. postponed, until the consequences can be evaluated
C. immediate, because we cannot afford any more bank failures
D. accelerated, to Overcome legislative fear
对于宽浅变迁的河段,应采用间接防护中的( )用以挑流或减小流速,减轻水流对河岸或路基的冲刷。
A. 护坝
B. 丁坝
C. 顺坝
D. 改移河道
管式渗沟的管壁应设(),交错布置,间距不宜大于20cm。
A. 泄水孔
B. 渗水孔
C. 排水孔
D. 隔水孔