A.最大 B.最小 C.安全 D.经济
A.30° B.45° C.60° D.90°
A.20~40mm B.50~100mm C.120~140mm D.150~200mm
A.50mm B.100mm C.150mm D.200mm
A、绞接法 B、绑接法 C、插接法 D、压接法