A.投影方向; B.旋轉(zhuǎn)方向; C.圖形配置方向; D.既是投影又是旋轉(zhuǎn)方向;
A.5∶1; B.2∶1; C.1∶2; D.1∶5;
A.鈣基潤滑脂; B.鈉基潤滑脂; C.鋰基潤滑脂; D.鉬基潤滑脂;