单项选择题
A.Short splice
B.Long splice
C.Back splice
D.Spindle splice
单项选择题 A small light tackle with blocks of steel or wood that is used for miscellaneous small jobs is called a().
单项选择题 A single heavy wire made up for the topping lift is called a().
单项选择题 A device used to enlarge the size of an existing bore hole,having teeth arranged on its outside circumference to cut the formation as it rotates is a(n)().