复合螺纹加工指令中的两侧交替切削法与单侧切削法在效果上的区别是（）。
A、加工效率
B、螺纹尺寸精度
C、改善刀具寿命
D、螺纹表面质量
参考答案：C
针刺天枢穴既能治疗腹泻又能治疗便秘是腧穴的（）
A.远治作用
B.近治作用
C.特殊作用
D.抗御病邪作用
E.运行气血作用
The maneuvering information required to be posted in the wheelhouse must be based on certain conditions.Which of the following is NOT one of these conditions?（）
A.The hull must be clean
B.There must be calm weather – wind 10 knots or less and a calm sea
C.There must be no currents
D.The depth of the water must be at least one and one-half times the draft
