如何提高复制率？
参考答案：增加PC料射速，增加3P、4P压力，增加start位，升高料温，降低1V和提高模温。
Mary _____ yet.I'm waiting for her.[ ]
A. came back
B. has come back
C. hasn't come back
D. was coming back
制品外观面如果不需要做皮纹，可以不用做拔模斜度。
