浇注混泥土时，倾落自由高度不应超过（）米。
A、4
B、2
C、3
D、6
参考答案：B
储蓄国债（电子式）和记账式国债有什么主要区别？
.In recent years, Chinese traditional culture _______________ more and more fashionable.
A．has become
B．became
C．have become
D．had become
