闸底板上、下游端一般设有齿墙,因为有利于(),并()。
参考答案:抗滑稳定;可延长渗径
Thinking________you know _________in fact you don’t is a terrible mistake.
A.what;what
B.that;what
C.what;that
D.that;that
简述英国票据法规定的背书人的责任。