有些雕刻刀是由厨师根据需要用铜片、不锈钢片等自己设计制造的，没有统一的标准和规格。
参考答案：对
Great changes ______ in my hometown in the past few years.[ ]
A. were taken place
B. took place
C. have been taken place
D. have taken place
交叉配血试验注意事项有哪些？
