在一定切削用量的条件下，选用合适的（）进行充分冷却能提高钻头耐用度和断屑效果。
参考答案：切削液
She ________ her hairstyle in her hometown before she came to Chongqing for a better job.
A．would change
B．has changed
C．changed
D．was changing
单独海损具有哪些特点？
